CN109772465B - A kind of preparation method of water-soluble carbon dots modified perovskite catalytic material - Google Patents
A kind of preparation method of water-soluble carbon dots modified perovskite catalytic material Download PDFInfo
- Publication number
- CN109772465B CN109772465B CN201910072094.6A CN201910072094A CN109772465B CN 109772465 B CN109772465 B CN 109772465B CN 201910072094 A CN201910072094 A CN 201910072094A CN 109772465 B CN109772465 B CN 109772465B
- Authority
- CN
- China
- Prior art keywords
- perovskite
- fuel
- catalytic material
- water
- type catalytic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000003197 catalytic effect Effects 0.000 title claims abstract description 60
- 239000000463 material Substances 0.000 title claims abstract description 57
- 238000002360 preparation method Methods 0.000 title claims description 18
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title abstract description 57
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims abstract description 105
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 68
- 239000003054 catalyst Substances 0.000 claims abstract description 68
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 55
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 54
- 239000002243 precursor Substances 0.000 claims abstract description 48
- 239000000446 fuel Substances 0.000 claims abstract description 47
- 239000002816 fuel additive Substances 0.000 claims abstract description 47
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 47
- 239000008367 deionised water Substances 0.000 claims abstract description 43
- 229910021641 deionized water Inorganic materials 0.000 claims abstract description 43
- 150000001413 amino acids Chemical class 0.000 claims abstract description 42
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 36
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 36
- 239000004202 carbamide Substances 0.000 claims abstract description 35
- 239000002904 solvent Substances 0.000 claims abstract description 35
- 230000005496 eutectics Effects 0.000 claims abstract description 33
- 238000002156 mixing Methods 0.000 claims abstract description 27
- 229910052751 metal Inorganic materials 0.000 claims abstract description 25
- 239000002184 metal Substances 0.000 claims abstract description 25
- 238000000034 method Methods 0.000 claims abstract description 23
- 239000011259 mixed solution Substances 0.000 claims abstract description 21
- 150000001298 alcohols Chemical class 0.000 claims abstract description 15
- 238000003756 stirring Methods 0.000 claims abstract description 14
- 238000005303 weighing Methods 0.000 claims abstract description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 40
- 235000001014 amino acid Nutrition 0.000 claims description 40
- DHMQDGOQFOQNFH-UHFFFAOYSA-N Glycine Chemical compound NCC(O)=O DHMQDGOQFOQNFH-UHFFFAOYSA-N 0.000 claims description 25
- 229910021645 metal ion Inorganic materials 0.000 claims description 25
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 claims description 24
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims description 23
- 238000006243 chemical reaction Methods 0.000 claims description 15
- 239000004471 Glycine Substances 0.000 claims description 12
- 229910001964 alkaline earth metal nitrate Inorganic materials 0.000 claims description 12
- 239000000243 solution Substances 0.000 claims description 12
- 229910002001 transition metal nitrate Inorganic materials 0.000 claims description 12
- 229910001994 rare earth metal nitrate Inorganic materials 0.000 claims description 10
- USFZMSVCRYTOJT-UHFFFAOYSA-N Ammonium acetate Chemical compound N.CC(O)=O USFZMSVCRYTOJT-UHFFFAOYSA-N 0.000 claims description 8
- 239000005695 Ammonium acetate Substances 0.000 claims description 8
- KDXKERNSBIXSRK-UHFFFAOYSA-N Lysine Natural products NCCCCC(N)C(O)=O KDXKERNSBIXSRK-UHFFFAOYSA-N 0.000 claims description 8
- 239000004472 Lysine Substances 0.000 claims description 8
- AYFVYJQAPQTCCC-UHFFFAOYSA-N Threonine Natural products CC(O)C(N)C(O)=O AYFVYJQAPQTCCC-UHFFFAOYSA-N 0.000 claims description 8
- 239000004473 Threonine Substances 0.000 claims description 8
- 229940043376 ammonium acetate Drugs 0.000 claims description 8
- 235000019257 ammonium acetate Nutrition 0.000 claims description 8
- XUJNEKJLAYXESH-UHFFFAOYSA-N cysteine Natural products SCC(N)C(O)=O XUJNEKJLAYXESH-UHFFFAOYSA-N 0.000 claims description 8
- 235000018417 cysteine Nutrition 0.000 claims description 8
- 229960005150 glycerol Drugs 0.000 claims description 8
- 229940113115 polyethylene glycol 200 Drugs 0.000 claims description 8
- 229940068918 polyethylene glycol 400 Drugs 0.000 claims description 8
- 239000004475 Arginine Substances 0.000 claims description 7
- 239000002202 Polyethylene glycol Substances 0.000 claims description 7
- 229920002472 Starch Polymers 0.000 claims description 7
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 claims description 7
- 229930006000 Sucrose Natural products 0.000 claims description 7
- ODKSFYDXXFIFQN-UHFFFAOYSA-N arginine Natural products OC(=O)C(N)CCCNC(N)=N ODKSFYDXXFIFQN-UHFFFAOYSA-N 0.000 claims description 7
- 229940093476 ethylene glycol Drugs 0.000 claims description 7
- 229920001223 polyethylene glycol Polymers 0.000 claims description 7
- 230000035484 reaction time Effects 0.000 claims description 7
- 235000019698 starch Nutrition 0.000 claims description 7
- 239000008107 starch Substances 0.000 claims description 7
- 239000005720 sucrose Substances 0.000 claims description 7
- MTCFGRXMJLQNBG-REOHCLBHSA-N (2S)-2-Amino-3-hydroxypropansäure Chemical compound OC[C@H](N)C(O)=O MTCFGRXMJLQNBG-REOHCLBHSA-N 0.000 claims description 6
- XUJNEKJLAYXESH-REOHCLBHSA-N L-Cysteine Chemical compound SC[C@H](N)C(O)=O XUJNEKJLAYXESH-REOHCLBHSA-N 0.000 claims description 6
- ODKSFYDXXFIFQN-BYPYZUCNSA-P L-argininium(2+) Chemical compound NC(=[NH2+])NCCC[C@H]([NH3+])C(O)=O ODKSFYDXXFIFQN-BYPYZUCNSA-P 0.000 claims description 6
- HNDVDQJCIGZPNO-YFKPBYRVSA-N L-histidine Chemical compound OC(=O)[C@@H](N)CC1=CN=CN1 HNDVDQJCIGZPNO-YFKPBYRVSA-N 0.000 claims description 6
- KDXKERNSBIXSRK-YFKPBYRVSA-N L-lysine Chemical compound NCCCC[C@H](N)C(O)=O KDXKERNSBIXSRK-YFKPBYRVSA-N 0.000 claims description 6
- AYFVYJQAPQTCCC-GBXIJSLDSA-N L-threonine Chemical compound C[C@@H](O)[C@H](N)C(O)=O AYFVYJQAPQTCCC-GBXIJSLDSA-N 0.000 claims description 6
- MTCFGRXMJLQNBG-UHFFFAOYSA-N Serine Natural products OCC(N)C(O)=O MTCFGRXMJLQNBG-UHFFFAOYSA-N 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 6
- HNDVDQJCIGZPNO-UHFFFAOYSA-N histidine Natural products OC(=O)C(N)CC1=CN=CN1 HNDVDQJCIGZPNO-UHFFFAOYSA-N 0.000 claims description 6
- 229940085675 polyethylene glycol 800 Drugs 0.000 claims description 6
- 238000007789 sealing Methods 0.000 claims description 6
- 238000005406 washing Methods 0.000 claims description 6
- 238000001354 calcination Methods 0.000 abstract description 2
- 238000002844 melting Methods 0.000 abstract 1
- 230000008018 melting Effects 0.000 abstract 1
- 239000000203 mixture Substances 0.000 abstract 1
- 239000000047 product Substances 0.000 description 24
- 229910002651 NO3 Inorganic materials 0.000 description 12
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 11
- 239000007833 carbon precursor Substances 0.000 description 10
- 239000002245 particle Substances 0.000 description 9
- 238000012360 testing method Methods 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 8
- 239000012855 volatile organic compound Substances 0.000 description 8
- 238000005054 agglomeration Methods 0.000 description 7
- 230000002776 aggregation Effects 0.000 description 7
- 150000001408 amides Chemical class 0.000 description 7
- 230000008901 benefit Effects 0.000 description 7
- 238000011156 evaluation Methods 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- 235000009697 arginine Nutrition 0.000 description 6
- 239000012467 final product Substances 0.000 description 6
- 239000000843 powder Substances 0.000 description 6
- 238000002441 X-ray diffraction Methods 0.000 description 5
- 230000015556 catabolic process Effects 0.000 description 5
- 238000006731 degradation reaction Methods 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- 238000001157 Fourier transform infrared spectrum Methods 0.000 description 4
- 239000007864 aqueous solution Substances 0.000 description 4
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 4
- 239000012159 carrier gas Substances 0.000 description 4
- 238000005336 cracking Methods 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 230000000593 degrading effect Effects 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 4
- 238000001027 hydrothermal synthesis Methods 0.000 description 4
- 229910001868 water Inorganic materials 0.000 description 4
- 229910014033 C-OH Inorganic materials 0.000 description 3
- 229910014570 C—OH Inorganic materials 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 230000033558 biomineral tissue development Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000002349 favourable effect Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000000376 reactant Substances 0.000 description 3
- 238000003980 solgel method Methods 0.000 description 3
- ODKSFYDXXFIFQN-BYPYZUCNSA-N L-arginine Chemical compound OC(=O)[C@@H](N)CCCN=C(N)N ODKSFYDXXFIFQN-BYPYZUCNSA-N 0.000 description 2
- 229930064664 L-arginine Natural products 0.000 description 2
- 235000014852 L-arginine Nutrition 0.000 description 2
- 229910002254 LaCoO3 Inorganic materials 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- WGLPBDUCMAPZCE-UHFFFAOYSA-N chromium trioxide Inorganic materials O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 2
- 238000000975 co-precipitation Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 125000000524 functional group Chemical group 0.000 description 2
- 238000010335 hydrothermal treatment Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229910052761 rare earth metal Inorganic materials 0.000 description 2
- -1 rare earth nitrate Chemical class 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 229910052723 transition metal Inorganic materials 0.000 description 2
- 150000003624 transition metals Chemical class 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- KRKNYBCHXYNGOX-UHFFFAOYSA-K Citrate Chemical compound [O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O KRKNYBCHXYNGOX-UHFFFAOYSA-K 0.000 description 1
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 1
- 206010028980 Neoplasm Diseases 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 150000004703 alkoxides Chemical class 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 150000001720 carbohydrates Chemical class 0.000 description 1
- 235000014633 carbohydrates Nutrition 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 238000010351 charge transfer process Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000009841 combustion method Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000007306 functionalization reaction Methods 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 238000007210 heterogeneous catalysis Methods 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 231100000053 low toxicity Toxicity 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000002114 nanocomposite Substances 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 239000010815 organic waste Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000013618 particulate matter Substances 0.000 description 1
- 125000001997 phenyl group Chemical class [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 150000002910 rare earth metals Chemical group 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 230000002468 redox effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000007142 ring opening reaction Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000001568 sexual effect Effects 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000002352 surface water Substances 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
Images
Landscapes
- Catalysts (AREA)
Abstract
本发明涉及一种水溶性碳点改性的钙钛矿型催化材料的制备方法，其包括以下步骤，1将氨基酸、醇类和尿素或柠檬酸按照比例混合，搅拌均匀直至形成透明的低共熔溶剂；2称取钙钛矿金属前驱体、燃料以及燃料添加剂混合搅拌搅拌，得到前驱物混合溶液，在650~850℃焙烧3‑6h，得到钙钛矿金属氧化物催化剂；3将透明的低共熔溶剂和钙钛矿金属氧化物催化剂与去离子水混合；4在180‑230℃下反应3‑7h；5冷却，洗涤过滤；6在80℃烘干，然后在600℃下焙烧1‑3h。本发明通过添加含碳前驱体即氨基酸、醇类和尿素或柠檬酸来优化处理钙钛矿型催化材料表面的物化性质，制得的改性后的钙钛矿型催化材料能够更高效地催化降解甲烷。
The present invention relates to a method for preparing a water-soluble carbon-dot modified perovskite-type catalytic material, which comprises the following steps: 1. Mix amino acids, alcohols and urea or citric acid in proportion, and stir them evenly until a transparent low-coated catalyst is formed. Melting solvent; 2. Weighing the perovskite metal precursor, fuel and fuel additives, mixing and stirring to obtain a precursor mixed solution, and calcining at 650-850 ° C for 3-6h to obtain the perovskite metal oxide catalyst; 3. A deep eutectic solvent and a perovskite metal oxide catalyst are mixed with deionized water; 4. React at 180-230°C for 3-7h; 5. Cool, wash and filter; 6. Dry at 80°C, then calcinate at 600°C 1 ‑3h. In the present invention, the physicochemical properties of the surface of the perovskite type catalytic material are optimized by adding carbon-containing precursors, namely amino acids, alcohols and urea or citric acid, and the prepared modified perovskite type catalytic material can catalyze more efficiently. Degrade methane.
Description
Technical Field
The invention belongs to the technical field of chemical industry, environmental protection and catalytic materials, and particularly relates to a preparation method of a modified perovskite type catalytic material.
Background
The organic matter is the main component of urban environment particulate matter, and is also PM and O3Important precursors. Most of industrial emission series Volatile Organic Compounds (VOCs) have obvious ' three-cause ' effect, become toxic tumors affecting the health of residents, and are environment-friendly ' bottles for restricting the development of national economyNeck ". With the tightening of the discharge standards of VOCs in China, places and industries, the deep mineralization of VOCs becomes inevitable.
VOCs components are complex, gas velocity and concentration fluctuation are large, and a thermal, ultraviolet and plasma coupling catalyst purification technology becomes the first choice. The efficiency of thermally catalyzing and oxidizing VOCs is high, and VOCs can be deeply mineralized into CO2And H2O, effectively avoiding secondary pollution, but having large energy consumption and high operation cost; if the ring opening temperature of the benzene series is about 200 ℃, and the complete mineralization needs to reach more than 350 ℃. The high-efficiency catalyst becomes the key of the deep mineralization technology of the VOCs.
Perovskite catalysts are of increasing interest to more and more researchers due to their excellent redox properties, hydrothermal stability, and ultra-long life, among others, as compared to high cost precious metals. For example, replacing ABO with exogenous cations3The a or B sites of (a) are used to modulate catalyst surface oxygen vacancies, making them viable alternatives to platinum-based noble metal materials (PGMs) in many catalytic applications. However, the preparation of perovskite catalysts requires higher temperatures and longer calcination times, resulting in lower surface areas and less efficient surface catalytic reactions. In order to increase the surface area of the reactant interacting with the substrate, research on porous perovskites of different morphologies has been conducted, using a templating method to form an ordered porosity material to increase the active contact area of the reactant with the material. Although the introduction of ordered porosity can significantly improve the catalytic activity of the metal oxide, this synthesis process is complex and uneconomical; other perovskite materials prepared by various wet chemical reaction processes, such as coprecipitation treatment, sol-gel treatment and hydrothermal treatment, also have various disadvantages, such as difficulty in simultaneously controlling the precipitation of cations in a solution in the coprecipitation method, often resulting in the separation of components; sol-gel techniques typically use expensive metal alkoxides as raw materials; hydrothermal processes generally require long reaction times. Therefore, there is a need to further explore and develop simpler, cheaper perovskite composite metal oxide technologies.
Disclosure of Invention
The invention aims to provide a preparation method of a water-soluble carbon-point modified perovskite-type catalytic material, wherein the physicochemical property of the surface of the perovskite-type catalytic material is optimized by adding carbon-containing precursors, namely amino acid, alcohol and urea or citric acid, and the prepared modified perovskite-type catalytic material can catalyze and degrade methane more efficiently; the preparation method provided by the invention is simple and efficient.
In order to achieve the above object, the preparation method of the present invention comprises the steps of,
(1) mixing amino acid, alcohol and urea or citric acid according to a proportion, and uniformly stirring until a transparent eutectic solvent is formed; the amino acid: alcohols: the molar ratio of urea or citric acid is 1: (4-6): (1-5);
(2) weighing a perovskite metal precursor, a fuel and a fuel additive, wherein the perovskite metal precursor is two or more of rare earth metal nitrate, transition metal nitrate and alkaline earth metal nitrate; the fuel is one of urea, glycine, sucrose or citric acid; the fuel additive is one of ammonium acetate, starch or polyethylene glycol;
dissolving a perovskite metal precursor in deionized water, controlling the molar concentration of total metal ions in the solution to be 0.5-2.0 mol/L, and then adding fuel and a fuel additive; the sum of the fuel and the fuel additive is 1 to 2 times of the sum of the total metal ions added before; the molar ratio of the fuel to the fuel additive is (2-5): 1; stirring for 0.5h at room temperature to obtain a precursor mixed solution, and roasting the precursor mixed solution for 3-6h at 650-850 ℃ to obtain a perovskite metal oxide catalyst;
(3) mixing the transparent eutectic solvent obtained in the step (1) and the perovskite obtained in the step (2)
Mixing the ore metal oxide catalyst with deionized water, and adding the deionized water according to the proportion of 2-10mL of deionized water added into the perovskite metal oxide catalyst obtained in the step (2) per gram; the mass ratio of the transparent eutectic solvent obtained in the step (1) to the perovskite metal oxide catalyst obtained in the step (2) is 1 (1-6);
(4) putting the product obtained in the step (3) into a reaction kettle, sealing and reacting for 3-7h at the temperature of 180-;
(5) naturally cooling, and alternately washing and filtering for 3-6 times by using ethanol and deionized water;
(6) and (4) drying the product obtained in the step (5) at 80 ℃, and then roasting for 1-3h at 600 ℃.
Further, in the step (1), the amino acid is selected from one of glycine, lysine, arginine, cysteine, threonine, serine or histidine.
Further, in the step (1), the alcohol is selected from one of ethylene glycol, glycerol, polyethylene glycol 200, polyethylene glycol 400 or polyethylene glycol 800.
Further, in step (1), the amino acid: alcohols: the molar ratio of urea or citric acid is 1: 6: 3.
further, in the step (2), it is characterized in that: the total metal ion molar concentration in the step (1) is 1 mol/L.
Further, in the step (2), it is characterized in that: the molar amount of the sum of the fuel and the fuel additive is 1.5 times the molar amount of the sum of all the metal ions added.
Further, in the step (2), it is characterized in that: the molar ratio of the fuel to the fuel additive is 4: 1.
further, in the step (3), the mass ratio of the transparent eutectic solvent obtained in the step (1) to the perovskite metal oxide catalyst obtained in the step (2) is 1: 2.
Further, in the step (4), the reaction temperature is 200 ℃ and the reaction time is 4 h.
Further, in the step (6), the product is dried at 80 ℃, heated to 600 ℃ at 3 ℃/min and then roasted at 600 ℃ for 1 h.
The invention has the following positive effects:
the preparation method is simple, adopts non-noble metal oxide as the main synthetic material of the catalyst, and has low cost.
According to the invention, the carbon point modified perovskite catalytic material is carried out through the eutectic solvent of amino acids, so that the surface water solubility of the perovskite is increasedThe physical and chemical properties of the surface of the modified surface are modified by the sexual groups, namely carboxyl, hydroxyl and amide; meanwhile, the catalyst is subjected to secondary crystallization through hydrothermal treatment, the particle agglomeration phenomenon caused by high-temperature roasting is improved, the particle enlargement of the perovskite metal oxide catalyst is inhibited, more active sites are exposed on the material, and the methane catalytic degradation performance of the perovskite metal oxide catalyst is improved. Compared with the existing perovskite catalyst, the carbon dot/perovskite composite methane catalyst obtained by the invention has the advantages that the methane T is50%The temperature is reduced by about 100 ℃.
Drawings
FIG. 1 is an activity test profile of the product of example 1;
FIG. 2 is an activity test profile of the product of example 2;
FIG. 3 is an XRD pattern of the product of example 1;
FIG. 4 is an XRD pattern of the product of example 2;
FIG. 5 is the FT-IR spectrum of the product of example 1;
FIG. 6 is the FT-IR spectrum of the product of example 2.
Detailed Description
Example 1
The embodiment provides a preparation method of a water-soluble carbon point modified perovskite type catalytic material, which comprises the following steps,
(1) mixing amino acid, alcohol and urea according to a proportion, wherein the urea can be replaced by citric acid, namely mixing the amino acid, the alcohol and the citric acid, and uniformly stirring until a transparent eutectic solvent DES is formed; the amino acid: alcohols: the molar ratio of urea or citric acid is 1: (4-6): (1-5); in the step (1), the amino acid is selected from one of glycine, lysine, arginine, cysteine, threonine, serine or histidine. In the step (1), the alcohol is selected from one of ethylene glycol, glycerol, polyethylene glycol 200, polyethylene glycol 400 or polyethylene glycol 800.
In the embodiment, urea is selected as a raw material, and the amino acid is arginine, specifically L-arginine; the alcohols are glycerol, amino acids: alcohols: the molar ratio of urea or citric acid is 1: 6: 3.
(2) weighing a perovskite metal precursor, a fuel and a fuel additive, wherein the perovskite metal precursor is two or more of rare earth metal nitrate, transition metal nitrate and alkaline earth metal nitrate; the fuel is one of urea, glycine, sucrose or citric acid; the fuel additive is one of ammonium acetate, starch or polyethylene glycol;
dissolving a perovskite metal precursor in deionized water, controlling the molar concentration of total metal ions in the solution to be 0.5-2.0 mol/L, and then adding fuel and a fuel additive; the sum of the fuel and the fuel additive is 1 to 2 times of the sum of the total metal ions added before; the molar ratio of the fuel to the fuel additive is (2-5): 1; stirring for 0.5h at room temperature to obtain a precursor mixed solution, and roasting the precursor mixed solution for 3-6h at 650-850 ℃ to obtain a perovskite metal oxide catalyst;
preferably, the obtained precursor mixed solution is transferred to an evaporation dish and placed in an electric furnace for presintering to obtain loose powder, and then roasting is carried out.
In the embodiment, the perovskite metal precursor is rare earth metal nitrate and transition metal nitric acid, and the rare earth metal nitrate and the transition metal nitric acid are respectively selected from nitrate of La and nitrate of Co; the fuel is urea; the fuel additive is ammonium acetate; the total metal ion molar concentration in the solution is 1 mol/L; the molar number of the sum of the fuel and the fuel additive is 1.5 times of the molar number of the sum of all the added metal ions; the molar ratio of fuel to fuel additive is 4: 1; roasting the precursor mixed solution at 700 ℃ for 3h to obtain a perovskite metal oxide catalyst;
(3) mixing the transparent eutectic solvent obtained in the step (1) and the perovskite obtained in the step (2)
Mixing the ore metal oxide catalyst with deionized water, and adding the deionized water according to the proportion of 2-10mL of deionized water added into the perovskite metal oxide catalyst obtained in the step (2) per gram; the mass ratio of the transparent eutectic solvent obtained in the step (1) to the perovskite metal oxide catalyst obtained in the step (2) is 1 (1-6);
in this example, the amount of deionized water added was added in accordance with the ratio of 2mL of deionized water per gram of perovskite metal oxide catalyst; the mass ratio of the eutectic solvent to the perovskite metal oxide catalyst is 1: 2.
(4) Putting the product obtained in the step (3) into a reaction kettle, sealing and reacting for 3-7h at the temperature of 180-; in the embodiment, in the step (4), the reaction temperature is 200 ℃ and the reaction time is 4 hours;
(5) naturally cooling, alternately washing with ethanol and deionized water, and filtering for 5 times;
(6) and (4) drying the product obtained in the step (5) at 80 ℃, and then roasting for 1-3h at 600 ℃.
In the embodiment, in the step (6), the product is dried at 80 ℃, heated to 600 ℃ at 3 ℃/min, and then roasted at 600 ℃ for 1 h. The water-soluble carbon dot modified perovskite-type catalytic material LaCoO of example 1 was obtained3。
Evaluation of perovskite-type catalytic Material LaCoO modified with aqueous solution of carbon Point formed by Using L-arginine and Glycerol as carbon precursors in example 1 with a catalytic evaluation apparatus3The prepared catalyst of example 1 was used in an amount of 1mL, carrier gas flow rate of 100 mL/min, and methane concentration of 10000 ppm. The picture of the activity test of the final product of this example 1 is shown in FIG. 1, from which it can be seen that T is50%=396 ℃, which shows that the perovskite type catalytic material LaCoO modified by carbon dots in example 1 of the invention3The catalytic degradation of methane has obvious advantages. The XRD pattern of the final product of this example 1 is shown in FIG. 3, from which it can be seen that the perovskite type catalytic material LaCoO modified by carbon dots of this example3Carbon species are formed on the surface. The FT-IR spectrum of the final product of example 1 is shown in FIG. 5, and it can be seen that the perovskite-type catalytic material modified by the carbon points of example 1 has the following: C-OH stretching vibration (3209--1），C-H（2921 cm-1），C=ONR（1664 cm-1) Surface hydroxyl and amide, etc. water soluble groups, and the proper chemically reactive groups are favorable for adsorbing and cracking methane molecules, so that the methane is catalyzed and degraded more efficiently.
Example 2
The embodiment provides a preparation method of a water-soluble carbon point modified perovskite type catalytic material, which comprises the following steps,
(1) mixing amino acid, alcohol and urea according to a proportion, wherein the urea can be replaced by citric acid, namely mixing the amino acid, the alcohol and the citric acid, and uniformly stirring until a transparent eutectic solvent DES is formed; the amino acid: alcohols: the molar ratio of urea or citric acid is 1: (4-6): (1-5); in the step (1), the amino acid is selected from one of glycine, lysine, arginine, cysteine, threonine, serine or histidine. In the step (1), the alcohol is selected from one of ethylene glycol, glycerol, polyethylene glycol 200, polyethylene glycol 400 or polyethylene glycol 800.
In the embodiment, citric acid is selected as a raw material, and amino acid is lysine; the alcohol is glycol, amino acid: alcohols: the molar ratio of urea or citric acid is 1: 5: 2.5.
(2) weighing a perovskite metal precursor, a fuel and a fuel additive, wherein the perovskite metal precursor is two or more of rare earth metal nitrate, transition metal nitrate and alkaline earth metal nitrate; the fuel is one of urea, glycine, sucrose or citric acid; the fuel additive is one of ammonium acetate, starch or polyethylene glycol;
dissolving a perovskite metal precursor in deionized water, controlling the molar concentration of total metal ions in the solution to be 0.5-2.0 mol/L, and then adding fuel and a fuel additive; the sum of the fuel and the fuel additive is 1 to 2 times of the sum of the total metal ions added before; the molar ratio of the fuel to the fuel additive is (2-5): 1; stirring for 0.5h at room temperature to obtain a precursor mixed solution, and roasting the precursor mixed solution for 3-6h at 650-850 ℃ to obtain a perovskite metal oxide catalyst; preferably, the obtained precursor mixed solution is transferred to an evaporation dish and placed in an electric furnace for presintering to obtain loose powder, and then roasting is carried out.
In the embodiment, the perovskite metal precursor is rare earth metal nitrate, transition metal nitrate and alkaline earth metal nitrate, and the rare earth metal nitrate, the transition metal nitrate and the alkaline earth metal nitrate are respectively selected from nitrate of La, nitrate of Mn and nitrate of Mg; the fuel is glycine; the fuel additive is ammonium acetate; the total metal ion molar concentration in the solution is 1.2 mol/L; the molar number of the sum of the fuel and the fuel additive is 2 times of the sum of the molar numbers of all the added metal ions; the molar ratio of fuel to fuel additive is 5: 1; roasting the precursor mixed solution at 800 ℃ for 5 hours to obtain a perovskite metal oxide catalyst;
(3) mixing the transparent eutectic solvent obtained in the step (1) and the perovskite obtained in the step (2)
Mixing the ore metal oxide catalyst with deionized water, and adding the deionized water according to the proportion of 2-10mL of deionized water added into the perovskite metal oxide catalyst obtained in the step (2) per gram; the mass ratio of the transparent eutectic solvent obtained in the step (1) to the perovskite metal oxide catalyst obtained in the step (2) is 1 (1-6);
in this example, the amount of deionized water added was added in accordance with the ratio of 7mL of deionized water per gram of perovskite metal oxide catalyst; the mass ratio of the eutectic solvent to the perovskite metal oxide catalyst is 1: 3.
(4) Putting the product obtained in the step (3) into a reaction kettle, sealing and reacting for 3-7h at the temperature of 180-; in the embodiment, in the step (4), the reaction temperature is 230 ℃ and the reaction time is 6 hours;
(5) naturally cooling, alternately washing and filtering with ethanol and deionized water for 6 times;
(6) and (4) drying the product obtained in the step (5) at 80 ℃, and then roasting for 1-3h at 600 ℃.
In the embodiment, in the step (6), the product is dried at 80 ℃, heated to 600 ℃ at 3 ℃/min, and then roasted at 600 ℃ for 3 h. The water-soluble carbon dot modified perovskite type catalytic material LaMn of example 2 is obtained0.9Mg0.1O3。
By means of catalytic evaluation devicesEvaluation of the perovskite-type catalytic Material LaMn modified with an aqueous solution of carbon points formed by lysine and ethylene glycol as carbon precursors in example 20.9Mg0.1O3The prepared catalyst of example 2 was taken as 1mL, the carrier gas flow rate was 100 mL/min, and the methane concentration was 10000 ppm. The activity test picture of the final product obtained in this example 2 is shown in FIG. 2, from which it can be seen that T is50%=421 ℃, which shows that the perovskite catalytic material modified by the water-soluble carbon dots of example 2 of the present invention has a significant advantage in catalytic degradation of methane.
The XRD pattern of the final product of example 2 is shown in FIG. 4, from which it can be seen that carbon substances are formed on the surface of the perovskite-type catalytic material modified by the water-soluble carbon dots of this example. The FT-IR spectrum of the final product of example 2 is shown in FIG. 6, and it can be seen that the perovskite-type catalytic material modified by the water-soluble carbon dots of the example has the following: C-OH stretching vibration (3209--1），C-H（2921 cm-1），C=ONR（1664 cm-1) Surface hydroxyl and amide, etc. water soluble groups, and the proper chemically reactive groups are favorable for adsorbing and cracking methane molecules, so that the methane is catalyzed and degraded more efficiently.
Example 3
The embodiment provides a preparation method of a water-soluble carbon point modified perovskite type catalytic material, which comprises the following steps,
(1) mixing amino acid, alcohol and urea according to a proportion, wherein the urea can be replaced by citric acid, namely mixing the amino acid, the alcohol and the citric acid, and uniformly stirring until a transparent eutectic solvent DES is formed; the amino acid: alcohols: the molar ratio of urea or citric acid is 1: (4-6): (1-5); in the step (1), the amino acid is selected from one of glycine, lysine, arginine, cysteine, threonine, serine or histidine. In the step (1), the alcohol is selected from one of ethylene glycol, glycerol, polyethylene glycol 200, polyethylene glycol 400 or polyethylene glycol 800.
In the embodiment, urea is selected as a raw material, and the amino acid is threonine; the alcohol is polyethylene glycol 200, amino acid: alcohols: the molar ratio of urea or citric acid is 1: 4: 1.
(2) weighing a perovskite metal precursor, a fuel and a fuel additive, wherein the perovskite metal precursor is two or more of rare earth metal nitrate, transition metal nitrate and alkaline earth metal nitrate; the fuel is one of urea, glycine, sucrose or citric acid; the fuel additive is one of ammonium acetate, starch or polyethylene glycol;
dissolving a perovskite metal precursor in deionized water, controlling the molar concentration of total metal ions in the solution to be 0.5-2.0 mol/L, and then adding fuel and a fuel additive; the sum of the fuel and the fuel additive is 1 to 2 times of the sum of the total metal ions added before; the molar ratio of the fuel to the fuel additive is (2-5): 1; stirring for 0.5h at room temperature to obtain a precursor mixed solution, and roasting the precursor mixed solution for 3-6h at 650-850 ℃ to obtain a perovskite metal oxide catalyst;
preferably, the obtained precursor mixed solution is transferred to an evaporation dish and placed in an electric furnace for presintering to obtain loose powder, and then roasting is carried out.
In the embodiment, the perovskite metal precursor is alkaline earth metal nitrate and transition metal nitrate, and the alkaline earth metal nitrate and the transition metal nitrate are respectively selected from nitrate of Ca and nitrate of Fe; the fuel is sucrose; the fuel additive is starch; the total metal ion molar concentration in the solution is 0.5 mol/L; the molar number of the sum of the fuel and the fuel additive is 1 time of the sum of the molar numbers of all the added metal ions; the molar ratio of fuel to fuel additive is 2: 1; roasting the precursor mixed solution at 650 ℃ for 4h to obtain a perovskite metal oxide catalyst;
(3) mixing the transparent eutectic solvent obtained in the step (1) and the calcium obtained in the step (2)
Mixing the titanium ore metal oxide catalyst with deionized water, and adding the deionized water according to the proportion of 2-10mL of deionized water added into the perovskite metal oxide catalyst obtained in the step (2) per gram; the mass ratio of the transparent eutectic solvent obtained in the step (1) to the perovskite metal oxide catalyst obtained in the step (2) is 1 (1-6);
in this example, the amount of deionized water added was added in accordance with the ratio of 10mL of deionized water per gram of perovskite metal oxide catalyst; the mass ratio of the eutectic solvent to the perovskite metal oxide catalyst is 1: 6.
(4) Putting the product obtained in the step (3) into a reaction kettle, sealing the reaction kettle and then performing temperature rise at 180℃ and 230 DEG C
Reacting for 3-7 h; in the embodiment, in the step (4), the reaction temperature is 210 ℃ and the reaction time is 7 hours;
(5) naturally cooling, alternately washing with ethanol and deionized water, and filtering for 4 times;
(6) and (4) drying the product obtained in the step (5) at 80 ℃, and then roasting for 2h at 600 ℃.
In the embodiment, in the step (6), the product is dried at 80 ℃, heated to 600 ℃ at 3 ℃/min, and then roasted at 600 ℃ for 3 h. The water-soluble carbon-point modified perovskite-type catalytic material CaFeO in example 3 was obtained3。
Evaluation of perovskite-type catalytic Material CaFeO modified with an aqueous solution of carbon points formed by threonine and polyethylene glycol 200 as carbon precursors in example 3 with a catalytic evaluation apparatus3The prepared catalyst of example 3 was taken as 1mL, the carrier gas flow rate was 100 mL/min, and the methane concentration was 10000 ppm. After testing, this example 3T50%=432 ℃, which shows that the perovskite-type catalytic material modified by carbon dots in example 3 of the present invention has a significant advantage in catalytic degradation of methane.
Example 4
The embodiment provides a preparation method of a water-soluble carbon point modified perovskite type catalytic material, which comprises the following steps,
(1) mixing amino acid, alcohol and urea according to a proportion, wherein the urea can be replaced by citric acid, namely mixing the amino acid, the alcohol and the citric acid, and uniformly stirring until a transparent eutectic solvent DES is formed; the amino acid: alcohols: the molar ratio of urea or citric acid is 1: (4-6): (1-5); in the step (1), the amino acid is selected from one of glycine, lysine, arginine, cysteine, threonine, serine or histidine. In the step (1), the alcohol is selected from one of ethylene glycol, glycerol, polyethylene glycol 200, polyethylene glycol 400 or polyethylene glycol 800.
In the embodiment, citric acid is selected as a raw material, and amino acid is cysteine; the alcohol is polyethylene glycol 400, amino acid: alcohols: the molar ratio of urea or citric acid is 1: 5: 5.
(2) weighing a perovskite metal precursor, a fuel and a fuel additive, wherein the perovskite metal precursor is two or more of rare earth metal nitrate, transition metal nitrate and alkaline earth metal nitrate; the fuel is one of urea, glycine, sucrose or citric acid; the fuel additive is one of ammonium acetate, starch or polyethylene glycol;
dissolving a perovskite metal precursor in deionized water, controlling the molar concentration of total metal ions in the solution to be 0.5-2.0 mol/L, and then adding fuel and a fuel additive; the sum of the fuel and the fuel additive is 1 to 2 times of the sum of the total metal ions added before; the molar ratio of the fuel to the fuel additive is (2-5): 1; stirring for 0.5h at room temperature to obtain a precursor mixed solution, and roasting the precursor mixed solution for 3-6h at 650-850 ℃ to obtain a perovskite metal oxide catalyst; preferably, the obtained precursor mixed solution is transferred to an evaporation dish and placed in an electric furnace for presintering to obtain loose powder, and then roasting is carried out.
In the embodiment, the perovskite metal precursor is rare earth nitrate, transition metal nitrate and alkaline earth metal nitrate, and the rare earth nitrate, the transition metal nitrate and the alkaline earth metal nitrate are respectively selected from nitrate of La, nitrate of Cr and nitrate of Sr; the fuel is citric acid; the fuel additive is polyethylene glycol; the total metal ion molar concentration in the solution is 2 mol/L; the molar number of the sum of the fuel and the fuel additive is 1.6 times of the molar number of the sum of all the added metal ions; the molar ratio of fuel to fuel additive was 3.8: 1; roasting the precursor mixed solution at 850 ℃ for 65 hours to obtain a perovskite metal oxide catalyst;
(3) mixing the transparent eutectic solvent obtained in the step (1) and the perovskite obtained in the step (2)
Mixing the ore metal oxide catalyst with deionized water, and adding the deionized water according to the proportion of 2-10mL of deionized water added into the perovskite metal oxide catalyst obtained in the step (2) per gram; the mass ratio of the transparent eutectic solvent obtained in the step (1) to the perovskite metal oxide catalyst obtained in the step (2) is 1 (1-6);
in this example, the amount of deionized water added was added in accordance with the ratio of 3mL of deionized water per gram of perovskite metal oxide catalyst; the mass ratio of the eutectic solvent to the perovskite metal oxide catalyst is 1: 1.
(4) Putting the product obtained in the step (3) into a reaction kettle, sealing and reacting for 3-7h at the temperature of 180-; in the embodiment, in the step (4), the reaction temperature is 180 ℃ and the reaction time is 3 hours;
(5) naturally cooling, alternately washing with ethanol and deionized water, and filtering for 3 times;
(6) and (4) drying the product obtained in the step (5) at 80 ℃, and then roasting for 1-3h at 600 ℃.
In the embodiment, in the step (6), the product is dried at 80 ℃, heated to 600 ℃ at 3 ℃/min, and then roasted at 600 ℃ for 1.5 h. The water-soluble carbon dot-modified perovskite-type catalytic material La of example 4 was obtained0.9Sr0.1CrO3。
Evaluation of perovskite-type catalytic Material La modified with aqueous solution of carbon dots formed with cysteine and polyethylene glycol 400 as carbon precursors in example 4 by means of a catalytic evaluation apparatus0.9Sr0.1CrO3The prepared catalyst of example 4 was taken as 1mL, the carrier gas flow rate was 100 mL/min, and the methane concentration was 10000 ppm. After testing, T of example 450%And the temperature is =445 ℃, which shows that the perovskite catalytic material modified by the water-soluble carbon dots has obvious advantages in the catalytic degradation of methane in the embodiment 4 of the invention.
Example 5
The embodiment is different from the embodiment 1 in that a eutectic solvent DES is not added as a carbon precursor; the remaining steps and parameters were the same as in example 1. That is, in this example, in the step (3), the eutectic solvent is not added, and "mixing the transparent eutectic solvent obtained in the step (1) and the perovskite metal oxide catalyst obtained in the step (2) with deionized water" is changed to "mixing the perovskite metal oxide catalyst obtained in the step (2) with deionized water".
Example 6
The embodiment is different from the embodiment 2 in that a eutectic solvent DES is not added as a carbon precursor; the remaining steps and parameters were the same as in example 2. That is, in this example, in the step (3), the eutectic solvent is not added, and "mixing the transparent eutectic solvent obtained in the step (1) and the perovskite metal oxide catalyst obtained in the step (2) with deionized water" is changed to "mixing the perovskite metal oxide catalyst obtained in the step (2) with deionized water".
Final products obtained in examples 1-2 and examples 5-6 and LaCoO3As received and LaMn0.9Mg0.1O3Specific surface area and activity tests were performed as such and the test results are shown in table 1.
Table 1 results of activity test
As can be seen from table 1 and fig. 1 to 6, (1) examples 1 to 2 are superior to respective corresponding examples 5 to 6, compared to examples 5 to 6, and a hydrothermal method is also employed, except that the examples 5 to 6 do not add the eutectic solvent DES, that is, amino acid and alcohol are not added as carbon precursors; 3-4 XRD patterns can show that carbon substances are formed on the surface of the perovskite material in the examples 1-2; surface functional group characterization of the synthesized carbon-point modified perovskite material from the FT-IR plots of fig. 5-6 clearly reveals the following for examples 1-2 as compared to examples 5-6: C-OH stretching vibration (3209--1），C-H（2921 cm-1），C=ONR（1664 cm-1) Surface hydroxyl groups and water-soluble groups such as amide, which are suitable chemically reactive groups for adsorbing and cracking methane molecules and thus catalytically degrading methane more efficiently, examples 1-2 are superior to examples 5-6. The hydrothermal method of the preparation method avoids hard particle agglomeration possibly formed at high temperature; the obtained powder has good dispersibility, no agglomeration, good crystal form and controllable shape, and can be used for improving the defects (low specific surface area) of the materials prepared by the traditional sol-gel method;
the dissolution and recrystallization of elementary solid particles can be promoted in the secondary crystallization process, and when the particle size is larger than the critical size, the particle can continue to grow as a crystal nucleus and has an inhibiting effect on the subsequent growth; meanwhile, the carbon substance can cause the crystal structure of the perovskite metal oxide to change, more oxygen vacancies are generated, more active sites are exposed, and therefore methane can be degraded more efficiently.
(2) Examples 5 to 6 and LaCoO, respectively3As received and LaMn0.9Mg0.1O3Compared with the original samples, the products of examples 5 to 6 are respectively superior to the original samples, and both products are not added with carbon precursors, but are different in preparation method, so that the hydrothermal method disclosed by the invention is used for reducing the agglomeration phenomenon of catalyst particles, increasing the specific surface area and obviously enhancing the exposure of active sites, thereby more efficiently catalyzing and degrading methane. This shows that the preparation method of the invention avoids the hard agglomeration of particles which can be formed at high temperature; the obtained powder has good dispersibility, no agglomeration, good crystal form and controllable shape, and can be used for overcoming the defects (low specific surface area) of the traditional sol-gel method for preparing materials.
The specific surface area of the perovskite type catalytic material modified by the carbon points reaches 20-25m2The surface is added with a large number of water-soluble groups such as hydroxyl, amide and the like, and carbonaceous substances are formed on the surface, so that the catalytic activity is obviously improved. Such as a traditional sol-gel process prepared perovskite metal oxide catalyst LaCoO3 T50%=492 ℃, the activity is obviously improved after the hydrothermal modification by carbon points, T50%The value is reduced by about 100 ℃ at most. The optimized treatment method of the catalyst can be applied to the preparation of various metal oxide materials, such as hexachlorophosphate metal oxideCompound catalysts, spinel metal oxide catalysts, and the like. The perovskite metal oxide subjected to metal ion and hydrothermal optimization treatment can improve catalytic activity, reduce energy consumption, reduce emission of industrial waste gas, automobile exhaust and the like, and bring great economic and social benefits.
In this study we used a solution combustion method to prepare the perovskite catalytic material. The method can quickly form a metastable state phase, and the mixing of initial reactants occurs in a liquid state in the reaction process, so that the uniformity and the stoichiometry of a reaction product are conveniently controlled; the process is quick and does not need special equipment.
CDs synthesized by using molecules such as citrate, carbohydrate, polymer-silicon dioxide nano composite materials and the like as carbon precursors are usually quasi-spherical nano particles through hydrothermal or microwave synthesis and other 'bottom-up' methods, and have uniform dispersion, no apparent agglomeration and particle diameter of 2-6 nm. The oxidized CDs have the oxygen content ranging from 5 to 50 percent, contain a large number of water-soluble groups such as carboxyl, hydroxyl and amide on the surface, have excellent water solubility and appropriate chemically reactive groups, and are used for further physical and chemical property modification of materials. The amino acid DES selected by the method is a low-toxicity green solvent, has good thermal and chemical stability and has no biological toxicity. The amino acid molecule contains two functional groups of amino and carboxyl, and part of the amino acid has hydrophilicity. The carbon points formed by the amino acid DES as a carbon precursor are bonded to the surface of the perovskite catalyst in a free form or a bond, and the conjugated structure of the carbon points can promote the adsorption of methane to the surface of the perovskite, so that the carbon points are activated by hydroxyl and oxygen-free groups. At the same time, strong interactions between the perovskite metal oxide and the CDs exist to stabilize the complex and facilitate the charge transfer process, resulting in enhanced catalytic performance. In the field of heterogeneous catalysis, the invention utilizes the advantage of CDs functionalization to modify the physicochemical property of the surface of the perovskite catalyst, thereby developing a perovskite type catalytic material capable of catalyzing and degrading organic waste gas more efficiently, and having important significance.
In conclusion, the invention optimizes and treats the physicochemical properties of the surface of the perovskite type catalytic material by adding the carbon-containing precursors, namely amino acid, alcohol and urea or citric acid, for example, water-soluble groups such as carboxyl, hydroxyl and amide on the surface of the perovskite type catalytic material are added, and the appropriate chemically reactive groups are favorable for adsorbing and cracking methane molecules, thereby more efficiently catalyzing and degrading methane. The preparation method provided by the invention is simple and efficient, and has important significance for preparing the catalyst.
Claims (10)
1. A preparation method of a water-soluble carbon point modified perovskite type catalytic material is characterized by comprising the following steps: which comprises the following steps of,
(1) mixing amino acid, alcohol and urea or citric acid according to a proportion, and uniformly stirring until a transparent eutectic solvent is formed; the amino acid: alcohols: the molar ratio of urea or citric acid is 1: (4-6): (1-5);
(2) weighing a perovskite metal precursor, a fuel and a fuel additive, wherein the perovskite metal precursor is more than two of rare earth metal nitrate, transition metal nitrate and alkaline earth metal nitrate; the fuel is one of urea, glycine, sucrose or citric acid; the fuel additive is one of ammonium acetate, starch or polyethylene glycol;
dissolving a perovskite metal precursor in deionized water, controlling the molar concentration of total metal ions in the solution to be 0.5-2.0 mol/L, and then adding fuel and a fuel additive; the sum of the fuel and the fuel additive is 1 to 2 times of the sum of the total metal ions added before; the molar ratio of the fuel to the fuel additive is (2-5): 1; stirring for 0.5h at room temperature to obtain a precursor mixed solution, and roasting the precursor mixed solution for 3-6h at 650-850 ℃ to obtain a perovskite metal oxide catalyst;
(3) mixing the transparent eutectic solvent obtained in the step (1) and the perovskite metal oxide catalyst obtained in the step (2) with deionized water, and adding the deionized water according to the proportion of 2-10mL of deionized water added in each gram of the perovskite metal oxide catalyst obtained in the step (2); the mass ratio of the transparent eutectic solvent obtained in the step (1) to the perovskite metal oxide catalyst obtained in the step (2) is 1 (1-6);
(4) putting the product obtained in the step (3) into a reaction kettle, sealing and reacting for 3-7h at the temperature of 180-;
(5) naturally cooling, and alternately washing and filtering for 3-6 times by using ethanol and deionized water;
(6) and (4) drying the product obtained in the step (5) at 80 ℃, and then roasting for 1-3h at 600 ℃.
2. The method for preparing a water-soluble carbon dot modified perovskite-type catalytic material as claimed in claim 1, wherein: in the step (1), the amino acid is selected from one of glycine, lysine, arginine, cysteine, threonine, serine or histidine.
3. The method for preparing a water-soluble carbon dot modified perovskite-type catalytic material as claimed in claim 1, wherein: in the step (1), the alcohol is selected from one of ethylene glycol, glycerol, polyethylene glycol 200, polyethylene glycol 400 or polyethylene glycol 800.
4. The method for preparing a water-soluble carbon dot modified perovskite-type catalytic material as claimed in claim 1, wherein: in step (1), the amino acid: alcohols: the molar ratio of urea or citric acid is 1: 6: 3.
5. the method for preparing a water-soluble carbon dot modified perovskite-type catalytic material as claimed in claim 1, wherein: in the step (2), the method is characterized in that: the total metal ion molar concentration is 1 mol/L.
6. The method for preparing a water-soluble carbon dot modified perovskite-type catalytic material as claimed in claim 1, wherein: in the step (2), the method is characterized in that: the molar amount of the sum of the fuel and the fuel additive is 1.5 times the molar amount of the sum of all the metal ions added.
7. The method for preparing a water-soluble carbon dot modified perovskite-type catalytic material as claimed in claim 1, wherein: in the step (2), the method is characterized in that: the molar ratio of the fuel to the fuel additive is 4: 1.
8. the method for preparing a water-soluble carbon dot modified perovskite-type catalytic material as claimed in claim 1, wherein: in the step (3), the mass ratio of the transparent eutectic solvent obtained in the step (1) to the perovskite metal oxide catalyst obtained in the step (2) is 1: 2.
9. The method for preparing a water-soluble carbon dot modified perovskite-type catalytic material as claimed in claim 1, wherein: in the step (4), the reaction temperature is 200 ℃ and the reaction time is 4 h.
10. The method for preparing a water-soluble carbon dot modified perovskite-type catalytic material as claimed in claim 1, wherein: in the step (6), the product is dried at 80 ℃, heated to 600 ℃ at 3 ℃/min and then roasted at 600 ℃ for 1 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910072094.6A CN109772465B (en) | 2019-01-25 | 2019-01-25 | A kind of preparation method of water-soluble carbon dots modified perovskite catalytic material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910072094.6A CN109772465B (en) | 2019-01-25 | 2019-01-25 | A kind of preparation method of water-soluble carbon dots modified perovskite catalytic material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109772465A CN109772465A (en) | 2019-05-21 |
| CN109772465B true CN109772465B (en) | 2021-10-22 |
Family
ID=66502393
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910072094.6A Active CN109772465B (en) | 2019-01-25 | 2019-01-25 | A kind of preparation method of water-soluble carbon dots modified perovskite catalytic material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109772465B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110193368B (en) * | 2019-06-21 | 2022-01-28 | 河北科技大学 | Preparation method of spinel type catalytic material |
| CN112011333B (en) * | 2020-08-12 | 2022-08-26 | 河北科技大学 | Nitrogen-containing carbon quantum dot and preparation method thereof |
| CN112345508B (en) * | 2020-11-12 | 2022-09-16 | 青岛大学 | Application of green fluorescent carbon quantum dots in tryptophan detection and tryptophan detection method |
| CN112371173B (en) * | 2020-11-27 | 2023-09-08 | 沈阳化工研究院有限公司 | Platinum-carbon catalyst applied to hydrogenation of m-nitrobenzenesulfonic acid and preparation method thereof |
| CN113428891A (en) * | 2021-05-31 | 2021-09-24 | 昆明理工大学 | Preparation method and application of nano cadmium sulfide |
| CN113578332A (en) * | 2021-08-23 | 2021-11-02 | 深圳明讯新材料科技有限公司 | Preparation method of catalyst for preparing new energy methane gas |
| CN114669320A (en) * | 2022-05-17 | 2022-06-28 | 贵州大学 | A kind of preparation method of CdS/g-C3N4 heterojunction photocatalyst based on deep eutectic solvent |
| CN115975627A (en) * | 2022-12-14 | 2023-04-18 | 无锡极电光能科技有限公司 | A kind of perovskite quantum dot composite material and its preparation method, quantum dot device |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103372447A (en) * | 2012-04-26 | 2013-10-30 | 北京化工大学 | A high specific surface area perovskite catalyst LaCo0.9Mg0.1O3 and its preparation method |
| KR20130137868A (en) * | 2012-06-08 | 2013-12-18 | 현대자동차주식회사 | Pervoskite catalyst for no oxidation and a fabrication process thereof |
| CN103466600A (en) * | 2013-09-26 | 2013-12-25 | 沈阳大学 | Preparation method of environment-friendly low-toxic fluorescent carbon nano particle liquor |
| CN103736515A (en) * | 2014-01-06 | 2014-04-23 | 西安建筑科技大学 | High-property absorption and wave absorption type catalyst for VOCs (Volatile Organic Chemicals) catalytic oxidation and preparation of catalyst |
| CN107376924A (en) * | 2017-07-17 | 2017-11-24 | 河北科技大学 | A kind of preparation method of multi-stage porous perovskite catalyst |
| CN109231183A (en) * | 2018-10-23 | 2019-01-18 | 辽宁大学 | A kind of citric acid is the carbon quantum dot and its preparation method and application of carbon source |
-
2019
- 2019-01-25 CN CN201910072094.6A patent/CN109772465B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103372447A (en) * | 2012-04-26 | 2013-10-30 | 北京化工大学 | A high specific surface area perovskite catalyst LaCo0.9Mg0.1O3 and its preparation method |
| KR20130137868A (en) * | 2012-06-08 | 2013-12-18 | 현대자동차주식회사 | Pervoskite catalyst for no oxidation and a fabrication process thereof |
| CN103466600A (en) * | 2013-09-26 | 2013-12-25 | 沈阳大学 | Preparation method of environment-friendly low-toxic fluorescent carbon nano particle liquor |
| CN103736515A (en) * | 2014-01-06 | 2014-04-23 | 西安建筑科技大学 | High-property absorption and wave absorption type catalyst for VOCs (Volatile Organic Chemicals) catalytic oxidation and preparation of catalyst |
| CN107376924A (en) * | 2017-07-17 | 2017-11-24 | 河北科技大学 | A kind of preparation method of multi-stage porous perovskite catalyst |
| CN109231183A (en) * | 2018-10-23 | 2019-01-18 | 辽宁大学 | A kind of citric acid is the carbon quantum dot and its preparation method and application of carbon source |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109772465A (en) | 2019-05-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109772465B (en) | A kind of preparation method of water-soluble carbon dots modified perovskite catalytic material | |
| CN111905714B (en) | Method for preparing spinel type catalyst with assistance of low-temperature plasma | |
| CN109364924B (en) | Magnetic nano ozone catalyst CoFe2O4And preparation method and application thereof | |
| CN111495352B (en) | Method for efficiently photo-catalytically oxidizing metal doped modified strontium titanate of elemental mercury | |
| CN110252367B (en) | Solvothermal method for preparing few-layer carbon nitride supported vanadium dioxide catalyst and desulfurization application thereof | |
| CN105597769A (en) | Preparation method of a nanocomposite metal oxide catalyst CeO2-Co3O4 with flake shape | |
| CN105668649A (en) | Preparation method and application of a cubic shape nano-Co3O4 catalyst | |
| CN108889301B (en) | Spinel type catalyst and preparation method thereof | |
| CN107857301A (en) | A kind of calcium swage Ca2Fe2O5Method for preparing catalyst | |
| CN110935309B (en) | A two-stage low-concentration VOC catalytic degradation method | |
| CN114433073B (en) | Manganese-based catalyst and preparation method and application thereof | |
| CN115041186B (en) | Fly ash geopolymer/CuMn composite material and application thereof | |
| CN103212419A (en) | Preparation method and application of catalyst for treating acrylonitrile contained waste gas | |
| CN114849698B (en) | Mesoporous Na-alpha-MnO 2 Catalyst, preparation method and application thereof | |
| CN115970679B (en) | A transition metal element supported cerium-based catalyst and its preparation method and use | |
| JP2021126599A (en) | Voc removal catalyst and method for producing the same | |
| CN115318303B (en) | Catalyst for removing soot particles of diesel vehicle at low temperature and preparation method thereof | |
| CN1170763C (en) | Perovskite-type La1-x-yBaxDyyMnO3 composite oxide ultrafine particles and preparation method thereof | |
| CN115106098A (en) | A kind of transition metal oxide catalyst and its preparation method and application | |
| CN113244929A (en) | Iron bismuth oxide Bi2Fe4O9Preparation method and application in organic wastewater treatment | |
| CN115920949A (en) | Manganese oxide octahedral molecular sieve Na-OMS-2 catalyst and preparation method and application thereof | |
| KR102270807B1 (en) | The CO2 Conversion Method Using Metal Oxides | |
| CN116870901B (en) | Amorphous neodymium-doped manganese-based oxide catalyst material and preparation method and application thereof | |
| CN115779892B (en) | Catalyst for efficiently removing mercury from flue gas and preparation method thereof | |
| CN119488929A (en) | A two-dimensional nitrogen-rich carbon nitride catalyst co-modified with copper and carbon, and its preparation method and application |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |