WO2015131484A1 - Cerium-molybdenum-zirconium composite oxide catalyst, preparation method therefor and application thereof - Google Patents

Cerium-molybdenum-zirconium composite oxide catalyst, preparation method therefor and application thereof Download PDF

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WO2015131484A1
WO2015131484A1 PCT/CN2014/083673 CN2014083673W WO2015131484A1 WO 2015131484 A1 WO2015131484 A1 WO 2015131484A1 CN 2014083673 W CN2014083673 W CN 2014083673W WO 2015131484 A1 WO2015131484 A1 WO 2015131484A1
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molybdenum
cerium
zirconium
catalyst
precursor
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贺泓
丁世鹏
刘福东
石晓燕
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中国科学院生态环境研究中心
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/24—Chromium, molybdenum or tungsten
    • B01J23/28—Molybdenum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9404—Removing only nitrogen compounds
    • B01D53/9409—Nitrogen oxides
    • B01D53/9413—Processes characterised by a specific catalyst
    • B01D53/9418—Processes characterised by a specific catalyst for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/206—Ammonium compounds
    • B01D2251/2062—Ammonia
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/206—Ammonium compounds
    • B01D2251/2067—Urea
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/20769—Molybdenum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/40—Mixed oxides
    • B01D2255/407—Zr-Ce mixed oxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/01—Engine exhaust gases
    • B01D2258/012—Diesel engines and lean burn gasoline engines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Definitions

  • Cerium-molybdenum-zirconium composite oxide catalyst preparation method thereof and use thereof
  • the invention relates to a cerium-molybdenum-zirconium composite oxide catalyst, a preparation method thereof and a use thereof, in particular to a cerium-molybdenum-zirconium composite oxide catalyst for selectively catalytically reducing nitrogen oxides, a preparation method thereof and a use thereof.
  • the NH 3 -SCR technique is a technique for selectively catalytically reducing nitrogen oxides (NO x ) with ammonia (NH 3 ) as a reducing agent in the presence of oxygen and in the presence of a catalyst.
  • NH 3 -SCR technique is widely used in mobile source and a stationary source NO x removal catalyst.
  • the NH 3 -SCR catalyst can be classified into a molecular sieve catalyst, an activated carbon catalyst, and a metal oxide catalyst depending on the active component.
  • Molecular sieve catalysts mainly include ZSM-5, HBEA, SSZ-34 and SAPO-34.
  • the active components supported mainly include transition metal elements such as Cu, Fe and Ce or rare earth metal elements, but the cost is high, which is not conducive to industrial production.
  • the carbon material of the activated carbon catalyst has problems such as high temperature resistance and wear.
  • one of the objects of the present invention is to provide a cerium-molybdenum-zirconium composite oxide catalyst.
  • the molar ratio of Ce ( ⁇ ) to Zr (zirconium) in the cerium-molybdenum-zirconium composite oxide catalyst of the present invention is 1:2; the molar ratio of Mo (molybdenum) to Ce ( ⁇ ) is 0.1 to 1.5.
  • the molar ratio of Mo to Ce is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, and the like.
  • the doping of molybdenum significantly increases the low-temperature activity of the catalyst and broadens the temperature window; and the cerium-zirconium oxide has high thermal stability, thereby improving the The thermal stability and sintering resistance of the cerium-molybdenum-zirconium composite oxide catalyst.
  • the molar ratio of Mo to Ce is 0.1, 0.3, 0.5, 0.7, 1.0, 1.5.
  • Another object of the present invention is to provide a process for producing a cerium-molybdenum-zirconium composite oxide catalyst which is one of the objects.
  • the preparation method of the cerium-molybdenum-zirconium composite oxide catalyst of the invention comprises the following steps:
  • the invention adopts a precipitating agent to precipitate a precursor solution containing cerium, molybdenum and zirconium elements, and the preparation process is simple and easy, low in cost, and easy to realize industrialization.
  • the precursor of the cerium is selected from any one or a combination of at least two of cerium chloride, cerium nitrate, cerium ammonium nitrate or cerium sulfate; the combination typically but not limited includes chlorinated A combination of cerium and cerium nitrate, a combination of cerium sulfate and cerium nitrate, a combination of cerium nitrate, cerium ammonium nitrate and cerium sulfate.
  • the precursor of the molybdenum is selected from the group consisting of a water-soluble molybdenum salt or a molybdate, preferably one selected from the group consisting of ammonium molybdate, ammonium dimolybdate, ammonium tetramolybdate, molybdenum nitrate, molybdenum chloride and molybdenum sulfate.
  • a combination of at least 2 typically but not limited to include a combination of ammonium molybdate and molybdenum chloride, a combination of molybdenum sulfate and molybdenum nitrate, a combination of ammonium dimolybdate and ammonium molybdate, ammonium dimolybdate , a combination of ammonium tetramolybdate and molybdenum chloride, molybdenum nitrate, chlorination A combination of molybdenum and molybdenum sulfate.
  • the precursor of zirconium is selected from any one or a combination of at least two of zirconium nitrate, zirconyl nitrate, and zirconium sulfate; the combination typically but not limited to includes a combination of zirconium nitrate and zirconyl nitrate, nitric acid A combination of zirconium and zirconium sulfate, a combination of zirconium nitrate and zirconium sulfate, a combination of zirconium nitrate, zirconyl nitrate and zirconium sulfate.
  • Step (1) of the present invention The preparation method of the precursor solution of cerium, molybdenum and zirconium is as follows:
  • the ruthenium precursor and the zirconium precursor were dissolved in deionized water, stirred well until completely dissolved, and then an aqueous solution in which the molybdenum precursor was dissolved was added, followed by stirring until the mixture was homogeneous.
  • the concentration of cerium in the precursor solution of cerium, molybdenum and zirconium is 0.06 ⁇ 0.1mol/L ; the concentration of molybdenum is 0.06a ⁇ 0.1amol/L; the concentration of zirconium is 0.12 ⁇ 0.2mol/L;
  • the concentration of cerium in the precursor solution of cerium, molybdenum or zirconium is 0.08 mol/L ; the concentration of molybdenum is 0.08 amol/L; and the concentration of zirconium is 0.16 mol/L.
  • the value of a is the same as the value of a in the general formula CeMo a Zr 2 O x of the cerium molybdenum zirconium composite oxide catalyst.
  • the precipitating agent is urea.
  • the molar ratio of the precipitating agent to the metal element is 8 to 15, such as 9, 10, 11, 12, 13, 14, etc., preferably 10; the metal element is bismuth, molybdenum, zirconium.
  • the stirring temperature of the step (2) is 80 to 95 ° C, for example, 82 ° C, 86 ° C, 89 ° C, 91 ° C, 94 ° C, etc., preferably 90 ° C; the stirring time is 8 ⁇ 15h, for example 9h, 10h, llh, 13h, 14h, etc., preferably 12h.
  • the preparation method of the cerium-molybdenum-zirconium composite oxide catalyst of the present invention comprises the following steps:
  • a third object of the present invention is to provide a method for selectively catalytically reducing nitrogen oxides using a cerium-molybdenum-zirconium composite oxide catalyst as described in one of the objects.
  • the method for selectively catalytically reducing nitrogen oxides comprises the following steps:
  • the supported catalyst in the step (1) is such that the catalyst is formed into a spherical or plate shape in the exhaust gas passage.
  • the nitrogen-containing air is selectively reduced to spray a reducing agent upstream of the catalyst, and the reducing agent and the exhaust gas are mixed to carry out a reduction reaction;
  • the reducing agent is ammonia or urea;
  • a preparation method of a cerium-molybdenum-zirconium composite oxide catalyst comprises the following steps:
  • Comparative Example 1 provides a cerium-zirconium composite oxide catalyst which does not contain elemental molybdenum, and is prepared by: (1) dissolving cerium nitrate and zirconium nitrate in deionized water, stirring well until completely dissolved, to obtain hydrazine, The precursor solution of zirconium, the concentration of cerium and zirconium ions in the precursor solution of cerium and zirconium is controlled as
  • a preparation method of a cerium-molybdenum-zirconium composite oxide catalyst comprises the following steps:
  • a preparation method of a cerium-molybdenum-zirconium composite oxide catalyst comprises the following steps:

Abstract

The present invention relates to a cerium-molybdenum-zirconium composite oxide catalyst. In the catalyst, the molar ratio of cerium to zirconium is 1:2 and the molar ratio of molybdenum to cerium is 0.1-1.5. By the present invention, the catalyst used for the conversion of nitrogen oxide, with wide temperature window, high conversion rate, excellent thermal stability and anti-sintering ability, is obtained by adjusting the ratio of cerium, molybdenum and zirconium in the cerium-molybdenum-zirconium composite oxide catalyst; and the preparation process is simple, low in cost and easily industrialized.

Description

一种铈钼锆复合氧化物催化剂、 其制备方法及用途 技术领域  Cerium-molybdenum-zirconium composite oxide catalyst, preparation method thereof and use thereof
本发明涉及一种铈钼锆复合氧化物催化剂、 其制备方法及用途， 具体涉及 一种用于选择性催化还原氮氧化物的铈钼锆复合氧化物催化剂、 其制备方法及 用途。  The invention relates to a cerium-molybdenum-zirconium composite oxide catalyst, a preparation method thereof and a use thereof, in particular to a cerium-molybdenum-zirconium composite oxide catalyst for selectively catalytically reducing nitrogen oxides, a preparation method thereof and a use thereof.
背景技术 Background technique
NH3-SCR技术为在富氧且有催化剂存在的条件下以氨 （NH3) 为还原剂， 选择性催化还原氮氧化物 （NOx) 的技术。 NH3-SCR技术被广泛应用于固定源 以及移动源 NOx催化去除。 The NH 3 -SCR technique is a technique for selectively catalytically reducing nitrogen oxides (NO x ) with ammonia (NH 3 ) as a reducing agent in the presence of oxygen and in the presence of a catalyst. NH 3 -SCR technique is widely used in mobile source and a stationary source NO x removal catalyst.
按照活性组分的不同， NH3-SCR催化剂可以分为分子筛催化剂、 活性炭催 化剂和金属氧化物催化剂。 分子筛催化剂主要有 ZSM-5、 HBEA、 SSZ-34 和 SAPO-34等， 负载的活性组分主要有 Cu、 Fe、 Ce等过渡金属元素或稀土金属元 素， 但是成本高， 不利于工业化生产。 活性炭催化剂的碳材料存在不耐高温、 易发生磨损等问题。金属氧化物催化剂中， V205-W03(Mo03yTi02是一种广泛使 用并已经工业化的催化剂， 但是该体系温度窗口较窄、 低温活性差、 高温条件 下容易发生烧结和晶型、 并且 V具有生物毒性。 因此迫切需要开发高效稳定、 环境友好的新型 NH3-SCR催化剂。 The NH 3 -SCR catalyst can be classified into a molecular sieve catalyst, an activated carbon catalyst, and a metal oxide catalyst depending on the active component. Molecular sieve catalysts mainly include ZSM-5, HBEA, SSZ-34 and SAPO-34. The active components supported mainly include transition metal elements such as Cu, Fe and Ce or rare earth metal elements, but the cost is high, which is not conducive to industrial production. The carbon material of the activated carbon catalyst has problems such as high temperature resistance and wear. In the metal oxide catalyst, V 2 0 5 -W0 3 (Mo0 3 yTi0 2 is a widely used and industrialized catalyst, but the temperature window of the system is narrow, the low temperature activity is poor, and the sintering and crystal form are prone to occur under high temperature conditions. And V is biologically toxic. Therefore, there is an urgent need to develop a novel, highly stable, environmentally friendly NH 3 -SCR catalyst.
Ce02作为汽油车尾气催化剂始于 20世纪 80年代， 在贫富燃工况交替运行 的条件下会发生 Ce4+ Ce3+氧化还原反应， 即在富燃工况下 Ce02释放出氧气， 贫燃工况下， 吸收和储存氧气。 （^02在高温时易发生烧结， 研究发现通过添加 Zr4+形成的铈锆固溶体具有比（^02更为显著的高温抗烧结能力。 近年来铈锆氧 化物也作为 NH3-SCR催化剂的活性组分用于 NOx催化去除。但是该催化剂存在 温度窗口窄，低温活性差等缺点，为了将其实际应用固定源或柴油车尾气中 NOx 的高效去除， 必须对其进行进一步的优化和改性。 Ce0 2 as a gasoline vehicle exhaust gas catalyst began in the 1980s, Ce 4 + Ce 3 + redox reaction occurs under the conditions of alternating rich and poor combustion conditions, that is, Ce0 2 releases oxygen under rich combustion conditions. Absorbs and stores oxygen under lean conditions. (^0 2 is prone to sintering at high temperatures. It has been found that the cerium-zirconium solid solution formed by the addition of Zr 4+ has a higher temperature resistance to sintering than ^0 2 . In recent years, cerium-zirconium oxide has also acted as NH 3 -SCR. the active component of the catalyst for the catalytic removal of NO x, but the presence of the catalyst A narrow temperature window, defects and poor low-temperature activity, its practical application in order to diesel exhaust from stationary sources or in efficient removal of NO x and must be further modified and optimized.
"铈锆基脱硝催化剂制备及抗中毒性能的研究" 中公开的钼优化的铈锆复 合氧化物催化剂 Ce。.5Zr。.5M0。.。502.15， 但其在空速为 SOOOh 条件下， 其对氮氧化 合物转化的温度窗口为 300〜400°C，最佳温度为 350°C，但转化率仅有 88% ("铈 锆基脱硝催化剂制备及抗中毒性能的研究"， 曾心如，南京工业大学， 硕士论文， 第五章）。 The molybdenum-optimized cerium-zirconium composite oxide catalyst Ce disclosed in "Study on Preparation and Anti-poisoning Performance of Zirconium-Based Denitration Catalyst". . 5 Z r . . 5 M 0 . . . . 5 0 2 . 15 , but its temperature window for the conversion of nitrogen oxides is 300~400 °C at an airspeed of SOOOh, and the optimum temperature is 350 °C, but the conversion rate is only 88% ("铈Preparation of Zirconium-Based Denitration Catalyst and Study on Anti-poisoning Performance", Zeng Xinru, Nanjing University of Technology, Master Thesis, Chapter 5).
因此， 本领域需要开发一种对氮氧化合物转化的温度窗口更宽， 转化率更 高， 热稳定性和抗烧结能力优异的铈钼锆复合氧化物催化剂。  Therefore, there is a need in the art to develop a cerium-molybdenum-zirconium composite oxide catalyst which has a wider temperature window for conversion of oxynitride, higher conversion, and excellent thermal stability and sintering resistance.
发明内容 Summary of the invention
为了解决现有铈钼锆复合氧化物催化剂温度窗口窄， 转化率低， 热稳定性 和抗烧结能力差等问题， 本发明的目的之一在于提供一种铈钼锆复合氧化物催 化剂。  In order to solve the problems of the prior enthalpy molybdenum-zirconium composite oxide catalyst having a narrow temperature window, low conversion rate, poor thermal stability and poor sintering resistance, one of the objects of the present invention is to provide a cerium-molybdenum-zirconium composite oxide catalyst.
本发明所述的铈钼锆复合氧化物催化剂中 Ce (铈） 和 Zr (锆） 的摩尔比为 1 :2； Mo (钼) 与 Ce (铈) 的摩尔比为 0.1〜1.5。  The molar ratio of Ce (铈) to Zr (zirconium) in the cerium-molybdenum-zirconium composite oxide catalyst of the present invention is 1:2; the molar ratio of Mo (molybdenum) to Ce (铈) is 0.1 to 1.5.
典型但非限制性的， Mo与 Ce的摩尔比为 0.2、 0.3、 0.4、 0.5、 0.6、 0.7、 0.8、 0.9、 1.0、 1.1、 1.2、 1.3、 1.4等。  Typically, but not limited, the molar ratio of Mo to Ce is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, and the like.
本发明制备得到的铈钼锆复合氧化物催化剂中， 由于钼的掺杂， 显著提高 了催化剂的低温活性， 拓宽了温度窗口； 而铈锆氧化物具有较高的热稳定性， 因而提高了所述铈钼锆复合氧化物催化剂的热稳定性和抗烧结能力。 另外， 本 发明对元素铈、 钼、 锆比例的优化选择， 起到了协同增效的作用， 大大提高了 铈钼锆复合氧化物在选择性催化还原氮氧化物的过程中的效率和 NOx转化率。 In the cerium-molybdenum-zirconium composite oxide catalyst prepared by the invention, the doping of molybdenum significantly increases the low-temperature activity of the catalyst and broadens the temperature window; and the cerium-zirconium oxide has high thermal stability, thereby improving the The thermal stability and sintering resistance of the cerium-molybdenum-zirconium composite oxide catalyst. Further, the present invention of the elements cerium, molybdenum, zirconium Optimization of ratio, a synergistic effect played, greatly improving the process of the cerium-zirconium composite oxide of molybdenum in the selective catalytic reduction of nitrogen oxides NO x conversion efficiency and rate.
优选地， 所述铈钼锆复合氧化物催化剂中， Mo与 Ce的摩尔比为 0.1、 0.3、 0.5、 0.7、 1.0、 1.5。 Preferably, in the cerium-molybdenum-zirconium composite oxide catalyst, the molar ratio of Mo to Ce is 0.1, 0.3, 0.5, 0.7, 1.0, 1.5.
优选地， 所述铈钼锆复合氧化物催化剂为 CeMoaZr2Ox， 其中， a为 0、 0.1、 0.3、 0.5、 0.7、 1.0、 1.5中的任意比例。 在所述铈钼锆复合氧化物催化剂的通式 CeMoaZr2Ox中， x的大小是根据通式中已确定的其他元素， 如 Ce、 Ti和 0的价 态和比例 a， 根据化合价态之和为 0计算得到的。 Preferably, the cerium-molybdenum-zirconium composite oxide catalyst is CeMo a Zr 2 O x , wherein a is any ratio of 0, 0.1, 0.3, 0.5, 0.7, 1.0, and 1.5. In the general formula CeMo a Zr 2 O x of the cerium-molybdenum-zirconium composite oxide catalyst, the size of x is based on other determinants of the formula, such as the valence state and ratio a of Ce, Ti and 0, according to the valence The sum of the states is 0.
本发明的目的之二是提供一种目的之一所述铈钼锆复合氧化物催化剂的制 备方法。  Another object of the present invention is to provide a process for producing a cerium-molybdenum-zirconium composite oxide catalyst which is one of the objects.
具体地， 本发明是通过如下技术方案实现的：  Specifically, the present invention is achieved by the following technical solutions:
本发明所述铈钼锆复合氧化物催化剂的制备方法包括如下步骤：  The preparation method of the cerium-molybdenum-zirconium composite oxide catalyst of the invention comprises the following steps:
( 1 ) 配制铈、 钼、 锆的前驱体溶液；  (1) preparing a precursor solution of bismuth, molybdenum and zirconium;
(2) 向步骤 （1 ) 得到的溶液中加入沉淀剂， 搅拌沉淀金属离子， 得到混 合液；  (2) adding a precipitant to the solution obtained in the step (1), stirring and precipitating the metal ions to obtain a mixed solution;
(3 ) 将步骤 （2) 得到的混合液冷却至室温后， 抽滤获得沉淀物， 将沉淀 物洗涤至中性， 然后经过干燥、 焙烧得到铈钼锆复合氧化物催化剂。  (3) After the mixture obtained in the step (2) is cooled to room temperature, a precipitate is obtained by suction filtration, and the precipitate is washed to neutrality, and then dried and calcined to obtain a cerium-molybdenum-zirconium composite oxide catalyst.
本发明采用沉淀剂沉淀含有铈、 钼、 锆元素的前驱体溶液， 制备过程简单 易行、 成本低廉， 容易实现工业化。  The invention adopts a precipitating agent to precipitate a precursor solution containing cerium, molybdenum and zirconium elements, and the preparation process is simple and easy, low in cost, and easy to realize industrialization.
优选地， 所述铈的前驱体选自氯化亚铈、 硝酸铈、 硝酸铈铵或硫酸铈中的 任意 1种或至少 2种的组合； 所述组合典型但非限制性的包括氯化亚铈和硝酸 铈的组合， 硫酸铈和硝酸铈的组合， 硝酸铈、 硝酸铈铵和硫酸铈的组合等。  Preferably, the precursor of the cerium is selected from any one or a combination of at least two of cerium chloride, cerium nitrate, cerium ammonium nitrate or cerium sulfate; the combination typically but not limited includes chlorinated A combination of cerium and cerium nitrate, a combination of cerium sulfate and cerium nitrate, a combination of cerium nitrate, cerium ammonium nitrate and cerium sulfate.
所述钼的前驱体选自能溶于水的钼盐或钼酸盐， 优选自钼酸铵、 二钼酸铵、 四钼酸铵、 硝酸钼、 氯化钼、 硫酸钼中的任意 1种或至少 2种的组合； 所述组 合典型但非限制性的包括钼酸铵和氯化钼的组合， 硫酸钼和硝酸钼的组合， 二 钼酸铵和钼酸铵的组合， 二钼酸铵、 四钼酸铵和氯化钼的组合， 硝酸钼、 氯化 钼和硫酸钼的组合等。 The precursor of the molybdenum is selected from the group consisting of a water-soluble molybdenum salt or a molybdate, preferably one selected from the group consisting of ammonium molybdate, ammonium dimolybdate, ammonium tetramolybdate, molybdenum nitrate, molybdenum chloride and molybdenum sulfate. Or a combination of at least 2; the combination typically but not limited to include a combination of ammonium molybdate and molybdenum chloride, a combination of molybdenum sulfate and molybdenum nitrate, a combination of ammonium dimolybdate and ammonium molybdate, ammonium dimolybdate , a combination of ammonium tetramolybdate and molybdenum chloride, molybdenum nitrate, chlorination A combination of molybdenum and molybdenum sulfate.
所述锆的前驱体选自硝酸锆、 硝酸氧锆、 硫酸锆中的任意 1种或至少 2种 的组合； 所述组合典型但非限制性的包括硝酸锆和硝酸氧锆的组合， 硝酸氧锆 和硫酸锆的组合， 硝酸锆和硫酸锆的组合， 硝酸锆、 硝酸氧锆和硫酸锆的组合 等。  The precursor of zirconium is selected from any one or a combination of at least two of zirconium nitrate, zirconyl nitrate, and zirconium sulfate; the combination typically but not limited to includes a combination of zirconium nitrate and zirconyl nitrate, nitric acid A combination of zirconium and zirconium sulfate, a combination of zirconium nitrate and zirconium sulfate, a combination of zirconium nitrate, zirconyl nitrate and zirconium sulfate.
本发明步骤 （1 ) 所述铈、 钼、 锆的前驱体溶液的配制方法为：  Step (1) of the present invention The preparation method of the precursor solution of cerium, molybdenum and zirconium is as follows:
将铈前驱体和锆前驱体溶于去离子水中， 充分搅拌至完全溶解后， 加入溶 解有钼前驱体的水溶液， 之后搅拌至混合均匀。  The ruthenium precursor and the zirconium precursor were dissolved in deionized water, stirred well until completely dissolved, and then an aqueous solution in which the molybdenum precursor was dissolved was added, followed by stirring until the mixture was homogeneous.
所述铈、 钼、 锆的前驱体溶液中， 铈的浓度为 0.06〜0.1mol/L; 钼的浓度为 0.06a〜0.1amol/L; 锆的浓度为 0.12〜0.2mol/L; The concentration of cerium in the precursor solution of cerium, molybdenum and zirconium is 0.06~0.1mol/L ; the concentration of molybdenum is 0.06a~0.1amol/L; the concentration of zirconium is 0.12~0.2mol/L;
优选地， 所述铈、 钼、 锆的前驱体溶液中， 铈的浓度为 0.08mol/L; 钼的浓 度为 0.08amol/L; 锆的浓度为 0.16mol/L。 Preferably, the concentration of cerium in the precursor solution of cerium, molybdenum or zirconium is 0.08 mol/L ; the concentration of molybdenum is 0.08 amol/L; and the concentration of zirconium is 0.16 mol/L.
其中， a的取值与铈钼锆复合氧化物催化剂的通式 CeMoaZr2Ox中 a的取值 相同。 Wherein, the value of a is the same as the value of a in the general formula CeMo a Zr 2 O x of the cerium molybdenum zirconium composite oxide catalyst.
本发明步骤 （2) 中， 所述沉淀剂为尿素。  In the step (2) of the present invention, the precipitating agent is urea.
优选地， 步骤 （2) 中， 所述沉淀剂与金属元素的摩尔比为 8〜15， 例如 9、 10、 11、 12、 13、 14等， 优选 10; 所述金属元素为铈、 钼、 锆。  Preferably, in step (2), the molar ratio of the precipitating agent to the metal element is 8 to 15, such as 9, 10, 11, 12, 13, 14, etc., preferably 10; the metal element is bismuth, molybdenum, zirconium.
优选地， 步骤 (2) 所述搅拌的温度为 80〜95°C， 例如 82°C、 86°C、 89°C、 91 °C、 94°C等， 优选 90°C ; 搅拌的时间为 8〜15h， 例如 9h、 10h、 llh、 13h、 14h 等， 优选 12h。  Preferably, the stirring temperature of the step (2) is 80 to 95 ° C, for example, 82 ° C, 86 ° C, 89 ° C, 91 ° C, 94 ° C, etc., preferably 90 ° C; the stirring time is 8~15h, for example 9h, 10h, llh, 13h, 14h, etc., preferably 12h.
本发明步骤 (3 )所述干燥的温度为 100〜110°C， 例如 102°C、 106°C、 109°C 等； 所述干燥的时间优选为 15〜28h， 例如 16h、 18h、 21h、 23h、 26h等， 进一 优选地，所述焙烧的温度为 400〜700°C，例如 402°C、 409°C、 415°C、 452°C、 475°C、 480°C、 550°C、 578°C、 664 °C、 685°C等， 优选 400〜500°C， 进一步优选 500 °C ; 所述焙烧的时间优选 l〜24h， 例如 3h、 10h、 17h、 23h等， 进一步优选 2〜8h， 最优选 3h。 The drying temperature in the step (3) of the present invention is 100 to 110 ° C, for example, 102 ° C, 106 ° C, 109 ° C, etc.; the drying time is preferably 15 to 28 h, for example, 16 h, 18 h, 21 h, 23h, 26h, etc., enter one Preferably, the calcination temperature is 400 to 700 ° C, for example, 402 ° C, 409 ° C, 415 ° C, 452 ° C, 475 ° C, 480 ° C, 550 ° C, 578 ° C, 664 ° C, 685 ° C, etc., preferably 400 to 500 ° C, further preferably 500 ° C ; the calcination time is preferably 1 to 24 h, such as 3 h, 10 h, 17 h, 23 h, etc., further preferably 2 to 8 h, and most preferably 3 h.
作为优选技术方案， 本发明所述铈钼锆复合氧化物催化剂的制备方法包括 如下步骤：  As a preferred technical solution, the preparation method of the cerium-molybdenum-zirconium composite oxide catalyst of the present invention comprises the following steps:
( 1 ) 以硝酸铈、 钼酸铵、 硝酸锆为前驱体溶于水， 配制铈、 钼、 锆的前驱 体溶液； 所述铈、 钼、 锆的前驱体溶液中， 铈的浓度为 0.08mol/L; 钼的浓度为 0.08amol/L; 锆的浓度为 0.16mol/L; (1) dissolving cerium nitrate, ammonium molybdate and zirconium nitrate as precursors in water to prepare a precursor solution of cerium, molybdenum and zirconium; in the precursor solution of cerium, molybdenum and zirconium, the concentration of cerium is 0.08 mol /L ; the concentration of molybdenum is 0.08 amol / L ; the concentration of zirconium is 0.16 mol / L;
(2)向步骤（1 )得到的溶液中加入尿素， 在 90 °C水浴条件下连续搅拌 12h 共沉淀金属离子， 得到混合液；  (2) adding urea to the solution obtained in the step (1), and continuously stirring the metal ions for 12 hours under a water bath condition of 90 ° C to obtain a mixed liquid;
(3 ) 将步骤 （2) 得到的混合液冷却至室温后， 抽滤获得沉淀物， 将沉淀 物洗涤至中性， 然后经过 100°C下的烘箱干燥， 500°C下焙烧 3h， 得到铈钼锆复 合氧化物催化剂。  (3) After cooling the mixture obtained in the step (2) to room temperature, the precipitate is obtained by suction filtration, the precipitate is washed to neutrality, and then dried in an oven at 100 ° C, and calcined at 500 ° C for 3 hours to obtain hydrazine. Molybdenum zirconium composite oxide catalyst.
本发明的目的之三是通过一种选择性催化还原氮氧化物的方法， 所述方法 使用如目的之一所述的铈钼锆复合氧化物催化剂。  A third object of the present invention is to provide a method for selectively catalytically reducing nitrogen oxides using a cerium-molybdenum-zirconium composite oxide catalyst as described in one of the objects.
优选地， 所述选择性催化还原氮氧化物的方法包括如下步骤：  Preferably, the method for selectively catalytically reducing nitrogen oxides comprises the following steps:
( 1 ) 负载催化剂；  (1) supporting a catalyst;
(2) 对含有氮氧化物的空气进行选择性催化还原。  (2) Selective catalytic reduction of air containing nitrogen oxides.
其中， 步骤 （1 ) 所述负载催化剂为将目的之一所述的铈钼锆复合氧化物催 化剂， 以涂层的形式涂覆在尾气流通通道的壁表面上， 所述尾气流通通道的壁 表面优选具有陶瓷或金属制成的蜂窝结构；  Wherein the supported catalyst is a cerium-molybdenum-zirconium composite oxide catalyst according to one of the objects, which is coated on the wall surface of the tail gas flow passage in the form of a coating, and the wall surface of the tail gas passage passage Preferably, it has a honeycomb structure made of ceramic or metal;
或， 步骤（1 )所述负载催化剂为将催化剂制成球状或板状置于尾气通道中。 其中， 步骤 （2) 所述对含有氮氧化物的空气进行选择性还原为在催化剂的 上游喷入还原剂， 还原剂和尾气混合后进行还原反应； 所述还原剂采用氨气或 尿素； Or, the supported catalyst in the step (1) is such that the catalyst is formed into a spherical or plate shape in the exhaust gas passage. Wherein, in step (2), the nitrogen-containing air is selectively reduced to spray a reducing agent upstream of the catalyst, and the reducing agent and the exhaust gas are mixed to carry out a reduction reaction; the reducing agent is ammonia or urea;
优选地， 所述含有氮氧化物的空气为移动源含氮氧化物气体或固定源含氮 氧化物气体， 优选柴油车尾气、 燃煤电厂烟气或工业窑炉烟气。  Preferably, the nitrogen oxide-containing air is a mobile source nitrogen oxide gas or a fixed source nitrogen oxide gas, preferably diesel exhaust gas, coal power plant flue gas or industrial furnace flue gas.
与现有技术相比， 本发明具有如下有益效果：  Compared with the prior art, the present invention has the following beneficial effects:
( 1 ) 本发明通过对铈钼锆复合氧化物催化剂中， 铈、 钼、 锆三种元素比例 的调节， 获得了温度窗口宽， 转化率高， 热稳定性和抗烧结能力优异的用于氮 氧化物转化的催化剂；  (1) The present invention obtains a nitrogen window, a high conversion rate, a high thermal stability and a sintering resistance for nitrogen by adjusting the ratio of lanthanum, molybdenum and zirconium in a cerium-molybdenum-zirconium composite oxide catalyst. a catalyst for the conversion of oxides;
以 MoasCe^i^Ox催化剂为例， 在 50000 反应空速条件下， 其温度窗口能 够达到 225°C〜450°C ; 氮氧化物最高转化率可达 100%; 700 °C焙烧后， 在 250°C 〜400°C之间转化率仍达 100%， 具有优异的抗烧结能力；  Taking MoasCe^i^Ox catalyst as an example, the temperature window can reach 225°C~450°C under the reaction space velocity of 50000; the highest conversion rate of nitrogen oxide can reach 100%; after calcination at 700 °C, at 250 The conversion rate between °C and 400 °C is still 100%, with excellent resistance to sintering;
(2) 本发明提供的铈钼锆复合氧化物催化剂用于氮氧化物的转化过程中， Mo显著提高了 3在催化剂表面的吸附和活化，从而有效提高了催化剂的反应 性能； (2) a cerium-zirconium composite oxide of molybdenum present invention provides a catalyst for the conversion of nitrogen oxides, Mo 3 significantly increased the adsorption and activation of the catalyst surface, thus effectively improving the performance of the catalyst of the reaction;
(3 )本发明提供的铈钼锆复合氧化物催化剂采用沉淀剂共沉淀铈钼锆前驱 体溶液的方法制备得到， 制备过程简单易行、 成本低廉， 容易实现工业化。 具体实 H ^式  (3) The cerium-molybdenum-zirconium composite oxide catalyst provided by the invention is prepared by a method of coprecipitating a cerium-molybdenum-zirconium precursor solution by a precipitating agent, and the preparation process is simple and easy, low in cost, and easy to realize industrialization. Concrete H ^
为更好地说明本发明， 便于理解本发明的技术方案， 本发明的典型但非限 制性的实施例如下：  In order to better explain the present invention, it is convenient to understand the technical solution of the present invention, and a typical but non-limiting embodiment of the present invention is as follows:
实施例 1〜6  Examples 1 to 6
一种铈钼锆复合氧化物催化剂的制备方法， 包括如下步骤：  A preparation method of a cerium-molybdenum-zirconium composite oxide catalyst comprises the following steps:
( 1 ) 将硝酸铈和硝酸锆溶于去离子水中， 充分搅拌至完全溶解后， 加入钼 酸铵水溶液， 之后加水至约 250mL得到铈、 钼、 锆的前驱体溶液， 控制铈、 钼、 锆的前驱体溶液中铈、 钼和锆离子的浓度； (1) Dissolving cerium nitrate and zirconium nitrate in deionized water, stirring well until completely dissolved, adding molybdenum An aqueous ammonium acid solution, followed by adding water to about 250 mL to obtain a precursor solution of cerium, molybdenum and zirconium, and controlling the concentration of cerium, molybdenum and zirconium ions in the precursor solution of cerium, molybdenum and zirconium;
(2 ) 向步骤 （1 ) 得到的铈、 钼、 锆的前驱体溶液中加入尿素， 在 90°C下 搅拌 12h沉淀金属离子， 得到混合液； 所述尿素和金属离子 （铈、 钼、 锆离子 摩尔数之和） 的摩尔比为 10;  (2) adding urea to the precursor solution of cerium, molybdenum and zirconium obtained in the step (1), and stirring the metal ions at 90 ° C for 12 hours to obtain a mixed liquid; the urea and metal ions (yttrium, molybdenum, zirconium) The molar ratio of the number of moles of ions) is 10;
(3 ) 将步骤 （2 ) 得到的混合液冷却至室温后， 抽滤获得沉淀物， 将沉淀 物洗涤至中性， 然后经过 100°C烘箱干燥， 500°C焙烧 3h， 得到铈钼锆复合氧化 物催化剂 CeMoaZr2Ox; (3) After cooling the mixture obtained in the step (2) to room temperature, the precipitate is obtained by suction filtration, and the precipitate is washed to neutrality, and then dried in an oven at 100 ° C, and calcined at 500 ° C for 3 hours to obtain a cerium-molybdenum-zirconium composite. Oxide catalyst CeMo a Zr 2 O x;
实施例 1〜6 中， 铈钼锆前驱体溶液中， 铈、 钼、 锆离子的浓度、 尿素与金 属离子 （铈钼锆离子摩尔数之和） 的摩尔比、 铈钼锆复合氧化物催化剂的组成 如表 1所示：  In Examples 1 to 6, the molar ratio of cerium, molybdenum, zirconium ions, the ratio of urea to metal ions (sum of moles of cerium molybdenum zirconium ions) in the cerium-molybdate-zirconium precursor solution, and the cerium-molybdenum-zirconium composite oxide catalyst The composition is shown in Table 1:
表 1 实施例 1〜6提供的铈钼锆复合氧化物催化剂操作条件列表  Table 1 List of operating conditions of the cerium-molybdenum-zirconium composite oxide catalyst provided in Examples 1 to 6
Figure imgf000008_0001
对比例 1提供一种铈锆复合氧化物催化剂， 其不含有元素钼， 制备方法为: ( 1 )将硝酸铈和硝酸锆溶于去离子水中， 充分搅拌至完全溶解后， 得到铈、 锆的前驱体溶液， 控制铈、 锆的前驱体溶液中铈和锆离子的浓度分别为
Figure imgf000008_0001
Comparative Example 1 provides a cerium-zirconium composite oxide catalyst which does not contain elemental molybdenum, and is prepared by: (1) dissolving cerium nitrate and zirconium nitrate in deionized water, stirring well until completely dissolved, to obtain hydrazine, The precursor solution of zirconium, the concentration of cerium and zirconium ions in the precursor solution of cerium and zirconium is controlled as
0.08mol/L、 0.16mol/L; 0.08mol/L, 0.16mol/L ;
(2 ) 向步骤 （1 ) 得到的铈、 锆的前驱体溶液中加入尿素， 在 90°C下搅拌 12h沉淀金属离子，得到混合液；所述尿素和金属离子（铈、锆离子摩尔数之和） 的摩尔比为 10;  (2) adding urea to the precursor solution of cerium and zirconium obtained in the step (1), and stirring the metal ions at 90 ° C for 12 hours to obtain a mixed liquid; the urea and metal ions (molar number of cerium and zirconium ions) And the molar ratio of 10;
(3 ) 将步骤 （2 ) 得到的混合液冷却至室温后， 抽滤获得沉淀物， 将沉淀 物洗涤至中性， 然后经过 100°C烘箱干燥， 500°C焙烧 3h， 得到铈锆复合氧化物 催化剂 Ce^ C 应用例 1  (3) After cooling the mixture obtained in the step (2) to room temperature, the precipitate is obtained by suction filtration, and the precipitate is washed to neutrality, and then dried in an oven at 100 ° C, and calcined at 500 ° C for 3 hours to obtain cerium-zirconium composite oxidation. Catalyst Ce^ C Application Example 1
应用实施例 1〜6和对比例 1提供的催化剂， 在固定床反应器上考察催化剂 活性。  Using the catalysts provided in Examples 1 to 6 and Comparative Example 1, the catalyst activity was examined on a fixed bed reactor.
催化剂的使用量分别为 0.6mL，反应混合气的组成为： [NO]=[NH3]=500ppm， The amount of catalyst used was 0.6 mL, and the composition of the reaction mixture was: [NO]=[NH 3 ]=500 ppm.
[02]=5%， N2作平衡气， 气体总流量为 500mL/min， 相应空速为 SO'OOOh—1 , 反应 温度 150〜500°C。 NO和 NH3及副产物N20， N02均利用红外气体池测定。 测试 结果如表 2所示： [0 2 ]=5%, N 2 is used as a balance gas, the total gas flow rate is 500 mL/min, the corresponding space velocity is SO'OOOh- 1 , and the reaction temperature is 150 to 500 °C. Both NO and NH 3 and by-products N 2 0, N0 2 were measured using an infrared gas cell. The test results are shown in Table 2:
表 2应用实施例 1〜6和对比例 1提供的催化剂的 NOx转化率 Examples 1~6 and NO x conversion catalyst of Comparative Example 1 of Table 2 provides embodiments Applications
Figure imgf000009_0001
例 3 Mo0.5CeiZr2Ox 5.19 51.87 100.00 100.00 100.00 100.00 76.86 40.53
Figure imgf000009_0001
Example 3 Mo 0 .5CeiZr 2 O x 5.19 51.87 100.00 100.00 100.00 100.00 76.86 40.53
4 6.34 48.38 100.00 100.00 100.00 99.27 74.36 34.314 6.34 48.38 100.00 100.00 100.00 99.27 74.36 34.31
5
Figure imgf000010_0001
5.22 40.81 100.00 100.00 99.76 92.55 57.70 15.615
Figure imgf000010_0001
5.22 40.81 100.00 100.00 99.76 92.55 57.70 15.61
6 Moi.5CeiZr2Ox 5.70 31.05 94.89 100.00 100.00 87.84 46.79 1.45 由表 2可以看出， Mo的添加拓宽了氮氧化合物转化率的温度窗口， 提高了 铈钼锆复合氧化物催化剂的催化活性： 对于 Mc^Ce^i^Ox其温度窗口能够达到 300°C〜400°C， NOx转化率能够达到 80%以上；对于 Mo^Ce^ Ox其温度窗口能 够达到 300°C〜400°C， NOx转化率能够达到 85%以上； 对于 Moo.sCe^ Ox和 Mo^Ce^ Ox其温度窗口能够达到 250°C〜400°C， NOx转化率能够达到 100%; 对于 ^101.(^612 (¾其温度窗口能够达到 250°C〜400°C， NOx转化率能够达到 90% 以上； 对于 Mo^Ce^ Ox其温度窗口能够达到 250°C〜400°C， NOx转化率能够 达到 85%以上； 6 Moi. 5 CeiZr 2 O x 5.70 31.05 94.89 100.00 100.00 87.84 46.79 1.45 It can be seen from Table 2 that the addition of Mo broadens the temperature window of the conversion of nitrogen oxides and improves the catalytic activity of the cerium-molybdenum-zirconium composite oxide catalyst: for Mc ^ Ce ^ i ^ Ox window temperature can reach 300 ° C~400 ° C, NO x conversion ratio can reach 80% or more; for Mo ^ Ce ^ Ox window temperature can reach 300 ° C~400 ° C, NO x conversion ratio can reach 85% or more; for Moo.sCe ^ Ox and Mo ^ Ce ^ Ox temperature window can reach 250 ° C~400 ° C, NO x conversion rate can reach 100%; for ^ 101 (. ^ 6 1 2 (¾ window temperature can reach 250 ° C~400 ° C, NO x conversion ratio can reach 90% or more; for Mo ^ Ce ^ Ox window temperature can reach 250 ° C~400 ° C, NO x Conversion rate can reach more than 85%;
分别将实施例 1〜6和对比例 1提供的催化剂在 700°C焙烧，测定其烧结后在 250〜400°C之间的NOX转化率；实施例 1〜6和对比例 1提供的催化剂经烧结后的 NOx最高转化率如表 3所示： Examples 1~6 and X are NO conversion after the catalyst of Comparative Example 1 provided 700 ° C calcination, sintering measured between 250~400 ° C in the embodiment; 1~6 and Comparative Example 1 to provide the catalyst in Example maximum NO x conversion after sintering are shown in table 3:
表 3实施例 1〜6和对比例 1提供的催化剂的经烧结后 NOx的最高转化率 The highest conversion rate of NO x after sintered three cases in Table 1~6 and Comparative Example 1 to provide the catalyst of the embodiment
Figure imgf000010_0002
5 Moi.0CeiZr2Ox 100
Figure imgf000010_0002
5 Moi. 0 CeiZr 2 O x 100
6 Moi.5CeiZr2Ox 100 6 Moi. 5 CeiZr 2 O x 100
由表 3可以看出，实施例 1〜6提供的铈锆钼复合氧化物催化剂在经过 700 °C 焙烧后， 200〜400°C下， NOx的最高转化率仍可达 100%， 具有优异的抗烧结能 力； 且由于 Mo的加入， 显著提高了 NH3在催化剂表面的吸附和活化， 使得实 施例 1〜6提供的铈锆钼复合氧化物催化剂的反应性能得到了明显的提高。 对比例 2 As can be seen from Table 3, the cerium-zirconium composite oxide of molybdenum catalyst of Example 1~6 embodiment provided after firing 700 ° C, at 200~400 ° C, the maximum conversion was 100% of NO x, is excellent The anti-sintering ability; and due to the addition of Mo, the adsorption and activation of NH 3 on the catalyst surface are remarkably improved, so that the reaction performance of the cerium-zirconium-molybdenum composite oxide catalyst provided in Examples 1 to 6 is remarkably improved. Comparative example 2
选用文献 "铈锆基脱硝催化剂制备及抗中毒性能的研究， 曾心如， 南京工 业大学， 硕士论文， 第五章"提供的钼优化的 Ce。.5Zr。.502复合氧化物催化剂作 为对比例 2。 The literature "Zirconium-based denitration catalyst preparation and anti-poisoning performance research, Zeng Xinru, Nanjing University of Technology, Master thesis, Chapter 5" provides molybdenum-optimized Ce. . 5 Zr. A 50 2 composite oxide catalyst was used as Comparative Example 2.
对于对比例 2， 其在较低空速 SOOOh 的条件下转化率最高仅为 85%左右， 远低于本申请在 SO'OOOh 较高空速下的转化率， 温度窗口也只有 300°C〜400°C， 较本申请窄。 实施例 7  For Comparative Example 2, the conversion rate is only about 85% at the lower space velocity SOOOh, which is much lower than the conversion rate at the higher airspeed of SO'OOOh, and the temperature window is only 300 °C~400. °C, narrower than this application. Example 7
一种铈钼锆复合氧化物催化剂的制备方法， 包括如下步骤：  A preparation method of a cerium-molybdenum-zirconium composite oxide catalyst comprises the following steps:
( 1 ) 将铈前驱体和锆前驱体溶于去离子水中， 充分搅拌至完全溶解后， 加 入钼前驱体的水溶液， 之后加水至约 250mL得到铈、 钼、 锆的前驱体溶液， 控 制铈、钼、锆的前驱体溶液中铈的浓度为 0.06mol/L， 钼的浓度为 0.06mol/L， 锆 的浓度为 0.12mol/L;  (1) Dissolving the ruthenium precursor and the zirconium precursor in deionized water, stirring well until completely dissolved, adding an aqueous solution of the molybdenum precursor, and then adding water to about 250 mL to obtain a precursor solution of ruthenium, molybdenum and zirconium, and controlling the ruthenium, The concentration of cerium in the precursor solution of molybdenum and zirconium is 0.06 mol/L, the concentration of molybdenum is 0.06 mol/L, and the concentration of zirconium is 0.12 mol/L;
(2) 向步骤 （1 ) 得到的铈、 钼、 锆的前驱体溶液中加入尿素， 在 80°C下 搅拌沉淀金属离子， 得到混合液； 所述沉淀剂和金属离子 （铈、 钼、 锆离子之 和） 的摩尔比为 8; (2) adding urea to the precursor solution of cerium, molybdenum and zirconium obtained in the step (1), and precipitating metal ions by stirring at 80 ° C to obtain a mixed solution; the precipitating agent and metal ions (yttrium, molybdenum, zirconium) Ion And the molar ratio of 8;
(3 ) 将步骤 （2) 得到的混合液冷却至室温后， 抽滤获得沉淀物， 将沉淀 物洗涤至中性， 然后经过 110°C烘箱干燥， 400°C焙烧 3h， 得到铈钼锆复合氧化 物催化剂；  (3) After cooling the mixture obtained in the step (2) to room temperature, the precipitate is obtained by suction filtration, and the precipitate is washed to neutrality, and then dried in an oven at 110 ° C and calcined at 400 ° C for 3 hours to obtain a cerium-molybdenum-zirconium composite. Oxide catalyst;
该催化剂在应用例 1 的测试条件下， 其氮氧化合物转化率的温度窗口为 250°C〜400°C，NOX转化率为 100%，焙烧 700°C后，其 NOx的最高转化率为 100%。 实施例 8 Application of the catalyst under test conditions in Example 1, the conversion of nitroxide compound temperature window of 250 ° C~400 ° C, NO X conversion was 100%, after firing 700 ° C, the maximum conversion of NO x which It is 100%. Example 8
一种铈钼锆复合氧化物催化剂的制备方法， 包括如下步骤：  A preparation method of a cerium-molybdenum-zirconium composite oxide catalyst comprises the following steps:
( 1 ) 将铈前驱体和锆前驱体溶于去离子水中， 充分搅拌至完全溶解后， 加 入钼前驱体的水溶液， 之后加水至约 250mL得到铈、 钼、 锆的前驱体溶液， 控 制铈、钼、锆的前驱体溶液中铈的浓度为 0.1mol/L， 钼的浓度为 0.1mol/L， 锆的 浓度为 0.2mol/L;  (1) Dissolving the ruthenium precursor and the zirconium precursor in deionized water, stirring well until completely dissolved, adding an aqueous solution of the molybdenum precursor, and then adding water to about 250 mL to obtain a precursor solution of ruthenium, molybdenum and zirconium, and controlling the ruthenium, The concentration of cerium in the precursor solution of molybdenum and zirconium is 0.1 mol/L, the concentration of molybdenum is 0.1 mol/L, and the concentration of zirconium is 0.2 mol/L;
(2) 向步骤 （1 ) 得到的铈、 钼、 锆的前驱体溶液中加入尿素， 在 95°C下 搅拌沉淀金属离子， 得到混合液； 所述沉淀剂和金属离子 （铈、 钼、 锆离子之 和） 的摩尔比为 15;  (2) adding urea to the precursor solution of cerium, molybdenum and zirconium obtained in the step (1), and precipitating the metal ions by stirring at 95 ° C to obtain a mixed solution; the precipitating agent and metal ions (yttrium, molybdenum, zirconium) The molar ratio of ions is 15;
(3 ) 将步骤 （2) 得到的混合液冷却至室温后， 抽滤获得沉淀物， 将沉淀 物洗涤至中性， 然后经过 100°C烘箱干燥， 700°C焙烧 3h， 得到铈钼锆复合氧化 物催化剂；  (3) After cooling the mixture obtained in the step (2) to room temperature, the precipitate is obtained by suction filtration, and the precipitate is washed to neutrality, then dried in an oven at 100 ° C, and calcined at 700 ° C for 3 hours to obtain a cerium-molybdenum-zirconium composite. Oxide catalyst;
该催化剂在应用例 1 的测试条件下， 其氮氧化合物转化率的温度窗口为 250°C〜400°C， NOx转化率为 100%，焙烧 700°C后，其 NOx转化率仍可达 100%， 没有明显降低。 应该注意到并理解， 在不脱离后附的权利要求所要求的本发明的精神和范 围的情况下， 能够对上述详细描述的本发明做出各种修改和改进。 因此， 要求 保护的技术方案的范围不受所给出的任何特定示范教导的限制。 Application of the catalyst under test conditions in Example 1, the conversion of nitroxide compound temperature window of 250 ° C~400 ° C, NO x conversion was 100%, after firing 700 ° C, conversion of NO x which is still Up to 100%, no significant reduction. It will be appreciated and appreciated that various modifications and improvements can be made to the invention described in the Detailed Description without departing from the spirit and scope of the invention. Therefore, the scope of the claimed technical solutions is not limited by any particular exemplary teachings presented.
申请人声明， 本发明通过上述实施例来说明本发明的详细方法， 但本发明 并不局限于上述详细方法， 即不意味着本发明必须依赖上述详细方法才能实施。 所属技术领域的技术人员应该明了， 对本发明的任何改进， 对本发明产品各原 料的等效替换及辅助成分的添加、 具体方式的选择等， 均落在本发明的保护范 围和公开范围之内。  The Applicant claims that the present invention is described by the above-described embodiments, but the present invention is not limited to the above detailed methods, that is, it does not mean that the present invention must be implemented by the above detailed methods. It will be apparent to those skilled in the art that any modifications of the present invention, equivalent substitution of the various materials of the product of the present invention, addition of auxiliary components, selection of specific means, and the like, are all within the scope of the present invention.

Claims

权 利 要 求 书 claims
1、 一种铈钼锆复合氧化物催化剂， 其特征在于， 所述催化剂中 Ce和 Zr的 摩尔比为 1 :2; Mo与 Ce的摩尔比为 0.1〜1.5。 1. A cerium-molybdenum-zirconium composite oxide catalyst, characterized in that the molar ratio of Ce and Zr in the catalyst is 1:2; the molar ratio of Mo to Ce is 0.1~1.5.
2、 如权利要求 1所述的催化剂， 其特征在于， 所述催化剂中， Mo与 Ce的 摩尔比为 0.1、 0.3、 0.5、 0.7、 1.0或 1.5; 2. The catalyst according to claim 1, wherein in the catalyst, the molar ratio of Mo to Ce is 0.1, 0.3, 0.5, 0.7, 1.0 or 1.5;
优选地， 所述催化剂为 CeMoaZr2Ox， 其中， a为 0.1、 0.3、 0.5、 0.7、 1.0或 1.5中的任意比例。 Preferably, the catalyst is CeMo a Zr 2 O x , where a is any ratio of 0.1, 0.3, 0.5, 0.7, 1.0 or 1.5.
3、 一种如权利要求 1或 2所述铈钼锆复合氧化物催化剂的制备方法， 其特 征在于， 所述方法包括如下步骤： 3. A method for preparing the cerium-molybdenum-zirconium composite oxide catalyst as claimed in claim 1 or 2, characterized in that the method includes the following steps:
( 1 ) 配制铈、 钼、 锆的前驱体溶液； (1) Prepare precursor solutions of cerium, molybdenum, and zirconium;
(2 ) 向步骤 （1 ) 得到的溶液中加入沉淀剂， 搅拌沉淀金属离子， 得到混 合液； (2) Add a precipitating agent to the solution obtained in step (1), stir to precipitate metal ions, and obtain a mixed solution;
(3 ) 将步骤 （2 ) 得到的混合液冷却至室温后， 抽滤获得沉淀物， 将沉淀 物洗涤至中性， 然后经过干燥、 焙烧得到铈钼锆复合氧化物催化剂。 (3) Cool the mixed solution obtained in step (2) to room temperature, filter it with suction to obtain a precipitate, wash the precipitate until neutral, and then dry and roast to obtain a cerium-molybdenum-zirconium composite oxide catalyst.
4、如权利要求 3所述的方法，其特征在于，所述铈的前驱体选自氯化亚铈、 硝酸铈、 硝酸铈铵或硫酸铈中的任意 1种或至少 2种的组合； 4. The method of claim 3, wherein the cerium precursor is selected from any one or a combination of at least two of cerium chloride, cerium nitrate, cerium ammonium nitrate or cerium sulfate;
所述钼的前驱体选自能溶于水的钼盐或钼酸盐， 优选自钼酸铵、 二钼酸铵、 四钼酸铵、 硝酸钼、 氯化钼或硫酸钼中的任意 1种或至少 2种的组合； The precursor of molybdenum is selected from water-soluble molybdenum salts or molybdates, preferably any one of ammonium molybdate, ammonium dimolybdate, ammonium tetramolybdate, molybdenum nitrate, molybdenum chloride or molybdenum sulfate. or a combination of at least 2;
所述锆的前驱体选自硝酸锆、 硝酸氧锆或硫酸锆中的任意 1种或至少 2种 的组合。 The precursor of zirconium is selected from any one or a combination of at least two of zirconium nitrate, zirconium oxynitrate or zirconium sulfate.
5、 如权利要求 3或 4所述的方法， 其特征在于， 步骤 （1 ) 所述铈、 钼、 锆的前驱体溶液的配制方法为： 5. The method according to claim 3 or 4, characterized in that the preparation method of the precursor solution of cerium, molybdenum and zirconium in step (1) is:
将铈前驱体和锆前驱体溶于去离子水中， 充分搅拌至完全溶解后， 加入溶 解有钼前驱体的水溶液， 之后搅拌至混合均匀； 所述铈、 钼、 锆的前驱体溶液中， 铈的浓度为 0.06〜0.1mol/L; 钼的浓度为 0.06a〜0.1amol/L; 锆的浓度为 0.12〜0.2mol/L; Dissolve the cerium precursor and the zirconium precursor in deionized water, stir thoroughly until completely dissolved, add the aqueous solution in which the molybdenum precursor is dissolved, and then stir until evenly mixed; In the precursor solution of cerium, molybdenum and zirconium, the concentration of cerium is 0.06~0.1mol/L ; the concentration of molybdenum is 0.06a~0.1amol/L; the concentration of zirconium is 0.12~0.2mol/L;
优选地， 所述铈、 钼、 锆的前驱体溶液中， 铈的浓度为 0.08mol/L; 钼的浓 度为 0.08amol/L; 锆的浓度为 0.16mol/L。 Preferably, in the precursor solution of cerium, molybdenum, and zirconium, the concentration of cerium is 0.08 mol/L ; the concentration of molybdenum is 0.08 amol/L; and the concentration of zirconium is 0.16 mol/L.
6、 如权利要求 3〜5之一所述的方法， 其特征在于， 所述沉淀剂为尿素； 优选地， 步骤 （2) 中， 所述沉淀剂与金属元素的摩尔比为 8〜15， 优选 10; 所述金属元素为铈、 钼、 锆； 6. The method according to one of claims 3 to 5, characterized in that the precipitating agent is urea; preferably, in step (2), the molar ratio of the precipitating agent to the metal element is 8 to 15, Preferably 10; the metal elements are cerium, molybdenum, and zirconium;
优选地， 步骤 （2) 所述搅拌的温度为 80〜95°C， 优选 90°C ; 搅拌的时间为 8〜15h， 优选 12h。 Preferably, the stirring temperature in step (2) is 80~95°C, preferably 90°C ; the stirring time is 8~15h, preferably 12h.
7、 如权利要求 3〜6 之一所述的方法， 其特征在于， 所述干燥的温度为 100〜110°C ;所述干燥的时间优选为 15〜28h，进一步优选 20〜26h，特别优选 24h; 优选地，所述焙烧的温度为 400〜700°C，优选 400〜500°C，进一步优选 500 °C； 所述焙烧的时间优选 l〜24h， 进一步优选 2〜8h， 最优选 3h。 7. The method according to one of claims 3 to 6, characterized in that the drying temperature is 100~110°C; the drying time is preferably 15~28h, further preferably 20~26h, particularly preferably 24h; Preferably, the roasting temperature is 400~700°C, preferably 400~500°C, and further preferably 500°C; the roasting time is preferably 1~24h, further preferably 2~8h, and most preferably 3h.
8、 一种选择性催化还原氮氧化物的方法， 其特征在于， 所述方法使用如权 利要求 1或 2所述的铈钼锆复合氧化物催化剂。 8. A method for selective catalytic reduction of nitrogen oxides, characterized in that the method uses the cerium-molybdenum-zirconium composite oxide catalyst as claimed in claim 1 or 2.
9、 如权利要求 8所述的方法， 其特征在于， 所述方法包括如下步骤： 9. The method of claim 8, characterized in that the method includes the following steps:
( 1 ) 负载催化剂； (1) Supported catalyst;
(2 ) 对含有氮氧化物的空气进行选择性催化还原。 (2) Selective catalytic reduction of air containing nitrogen oxides.
10、 如权利要求 9所述的方法， 其特征在于， 步骤 （1 ) 所述负载催化剂为 将权利要求 1或 2所述的铈钼锆复合氧化物催化剂， 以涂层的形式涂覆在尾气 流通通道的壁表面上， 所述尾气流通通道的壁表面优选具有陶瓷或金属制成的 或， 步骤（1 )所述负载催化剂为将催化剂制成球状或板状置于尾气通道中； 优选地， 步骤 （2)所述对含有氮氧化物的空气进行选择性还原为在催化剂 的上游喷入还原剂， 还原剂和尾气混合后进行还原反应； 所述还原剂采用氨气 或尿素； 10. The method according to claim 9, wherein the supported catalyst in step (1) is the cerium-molybdenum-zirconium composite oxide catalyst according to claim 1 or 2, which is coated on the exhaust gas in the form of a coating. On the wall surface of the circulation channel, the wall surface of the exhaust gas circulation channel is preferably made of ceramic or metal, and the supported catalyst in step (1) is to make the catalyst into a spherical or plate shape and place it in the exhaust channel; Preferably, the selective reduction of air containing nitrogen oxides in step (2) involves injecting a reducing agent upstream of the catalyst, and the reducing agent and tail gas are mixed to perform a reduction reaction; the reducing agent is ammonia or urea;
优选地， 所述含有氮氧化物的空气为移动源含氮氧化物气体或固定源含氮 氧化物气体， 优选柴油车尾气、 燃煤电厂烟气或工业窑炉烟气。 Preferably, the air containing nitrogen oxides is nitrogen oxide-containing gas from a mobile source or nitrogen oxide-containing gas from a fixed source, preferably diesel vehicle exhaust, coal-fired power plant flue gas or industrial kiln flue gas.
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* Cited by examiner, † Cited by third party
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CN103816891B (en) * 2014-03-04 2017-01-25 中国科学院生态环境研究中心 Cerium-molybdenum-zirconium composite oxide catalyst, and preparation method and application thereof
CN104368329B (en) * 2014-09-19 2017-03-15 中国科学院生态环境研究中心 A kind of cerium niobium zirconium mixed oxide catalyst, preparation method and its usage
CN105148961A (en) * 2015-07-21 2015-12-16 安徽省元琛环保科技有限公司 SCR flue gas denitrification catalyst and preparation method therefor
CN105561974B (en) * 2015-12-25 2018-11-13 南京工业大学 A kind of diesel engine vent gas SCR denitration catalyst and preparation method thereof
CN109364981A (en) * 2018-08-09 2019-02-22 江苏龙净科杰环保技术有限公司 Arsenical fume no vanadium denitration catalyst and its preparation process
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4719162A (en) * 1985-08-09 1988-01-12 Oji Paper Company, Ltd. Electrophotographically sensitive material for a litho printing plate
CN101314127A (en) * 2007-05-31 2008-12-03 中国科学院大连化学物理研究所 Oxide catalyst for selective reduction of nitrogen oxide, preparation and uses thereof
CN101528326A (en) * 2006-10-23 2009-09-09 尤米科尔股份公司及两合公司 Vanadium-free catalyst for selective catalytic reduction and process for its preparation
CN103301831A (en) * 2012-03-16 2013-09-18 中国科学院大连化学物理研究所 Catalyst for removing nitrogen oxide in emission exhaust and preparation method thereof
CN103442805A (en) * 2011-03-31 2013-12-11 恩亿凯嘉股份有限公司 Ammonia oxidation catalyst, exhaust gas purification device using same, and exhaust gas purification method
CN103816891A (en) * 2014-03-04 2014-05-28 中国科学院生态环境研究中心 Cerium-molybdenum-zirconium composite oxide catalyst, and preparation method and application thereof

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102861605B (en) * 2012-10-09 2014-09-17 西南石油大学 Diesel vehicle oxidation catalyst with low SO2 oxidation activity and preparation method of catalyst
CN103240079B (en) * 2013-05-30 2015-05-20 中国科学院生态环境研究中心 Cerium-zirconium-tungsten composite oxide catalyst as well as preparation method and usage thereof
CN103433025B (en) * 2013-09-05 2015-07-08 浙江大学 Preparation method of Ce-Zr-Cr composite oxide catalyst with stable zirconium

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4719162A (en) * 1985-08-09 1988-01-12 Oji Paper Company, Ltd. Electrophotographically sensitive material for a litho printing plate
CN101528326A (en) * 2006-10-23 2009-09-09 尤米科尔股份公司及两合公司 Vanadium-free catalyst for selective catalytic reduction and process for its preparation
CN101314127A (en) * 2007-05-31 2008-12-03 中国科学院大连化学物理研究所 Oxide catalyst for selective reduction of nitrogen oxide, preparation and uses thereof
CN103442805A (en) * 2011-03-31 2013-12-11 恩亿凯嘉股份有限公司 Ammonia oxidation catalyst, exhaust gas purification device using same, and exhaust gas purification method
CN103301831A (en) * 2012-03-16 2013-09-18 中国科学院大连化学物理研究所 Catalyst for removing nitrogen oxide in emission exhaust and preparation method thereof
CN103816891A (en) * 2014-03-04 2014-05-28 中国科学院生态环境研究中心 Cerium-molybdenum-zirconium composite oxide catalyst, and preparation method and application thereof

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