CN114314677A - Nano hydrated iron oxide and preparation method and application thereof - Google Patents
Nano hydrated iron oxide and preparation method and application thereof Download PDFInfo
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Abstract
The invention belongs to the technical field of catalysts, and provides a preparation method of nano hydrated iron oxide. The invention firstly prepares the mixed liquid respectively containing water-soluble ferric salt and precipitator, and then drops the mixed liquid containing precipitator into the mixed liquid containing water-soluble ferric salt for hydrothermal precipitation reaction, so as to obtain the nanoscale hydrated ferric oxide FeOOH, thereby ensuring the particle size uniformity and catalytic activity of the catalyst, and having simple preparation process and low cost; citric acid and ethanol are respectively added as dispersing agents in the process of preparing the two mixed solutions and are used for dispersing particles in the hydrothermal reaction process, so that the precipitation speed is controlled, the rapid growth of the particles is avoided, and the nano catalyst with smaller particles is obtained. The results of the embodiment show that the particle size of the hydrated iron oxide prepared by the preparation method provided by the invention is 15-25 nm; the catalyst was used for catalytic conversion of para-hydrogen, the concentration of para-hydrogen was 49.7%, and the conversion rate was 99.3%.
Description
Technical Field
The invention relates to the technical field of catalysts, in particular to a nano hydrated iron oxide and a preparation method and application thereof.
Background
The use of carbonaceous fuels will be greatly reduced in future society with hydrogen (H)2) The occupation ratio of the typical zero-carbon fuel is greatly improved, and the hydrogen energy industry is in the chance of rapid development. The hydrogen energy industry chain includes upstream hydrogen production, midstream storage and transportation, and downstream hydrogenation and end-use applications, however, currently H2The storage and transportation links greatly limit the development of the industry. The gaseous hydrogen is liquefied at low temperature (20K) and converted into liquid hydrogen (liquid hydrogen) with higher energy density, so that the storage and transportation problems of the hydrogen can be greatly solved, and the industrial development of hydrogen energy is accelerated. Para-hydrogen has a lower energy level than ortho-hydrogen, possesses good storage stability, and is less volatile, an ideal form of liquid hydrogen. In the process of hydrogen liquefaction, an ortho-para hydrogen conversion catalyst is needed to efficiently convert ortho-hydrogen into para-hydrogen.
The prior literature reports a plurality of preparation methods of the orthoparahydrogen conversion catalyst, for example, in patent CN112044457A, a supported orthoparahydrogen conversion catalyst is prepared by an impregnation method, however, the method needs to use strong acids and chloride salts such as hydrofluoric acid and ammonium chloride, which easily causes serious personal hazard and environmental pollution, and meanwhile, the method needs two-step high-temperature roasting, and the energy consumption of the preparation process is large; and the catalyst prepared by the impregnation method has the problems of large active component particles and uneven load, so that the catalytic activity of the catalyst is influenced. In another patent CN112844443A, a precursor salt is pre-impregnated in an ordered mesoporous molecular sieve and activated carbon to precipitate a hydroxide, and the obtained product is calcined at high temperature to obtain an ortho-para hydrogen conversion catalyst. Therefore, it is important to find a catalyst with simple preparation process, low cost and high catalytic activity.
Disclosure of Invention
The invention aims to provide the nano hydrated iron oxide and the preparation method and the application thereof.
In order to achieve the above purpose, the invention provides the following technical scheme:
the invention provides a preparation method of nano hydrated iron oxide, which comprises the following steps:
(1) dissolving water-soluble ferric salt and citric acid in water to obtain a mixed solution A;
(2) dissolving a precipitator and ethanol in water to obtain a mixed solution B;
(3) dropwise adding the mixed solution B obtained in the step (2) into the mixed solution A obtained in the step (1) to perform hydrothermal reaction to obtain nano hydrated iron oxide;
the steps (1) and (2) are not in sequence.
Preferably, the water-soluble ferric salt in step (1) comprises one or more of ferric nitrate, ferric chloride and ferric citrate.
Preferably, the concentration of the water-soluble ferric salt in the mixed solution A in the step (1) is 0.1-2 mol/L, and the concentration of the citric acid is 0.1-1 mol/L.
Preferably, the precipitant in step (2) comprises urea or ammonia water.
Preferably, the concentration of the precipitant in the mixed solution B in the step (2) is 1-10 mol/L, and the concentration of the ethanol is 1-5 mol/L.
Preferably, the volume ratio of the mixed solution a to the mixed solution B in the step (3) is 2: (1-2).
Preferably, the dropping speed in the step (3) is 1-8 mL/min.
Preferably, the temperature of the hydrothermal reaction in the step (3) is 70-200 ℃, and the time of the hydrothermal reaction is 8-16 h.
The invention provides the nano hydrated ferric oxide prepared by the preparation method in the technical scheme, wherein the particle size of the nano hydrated ferric oxide is 15-25 nm.
The invention also provides the application of the nano hydrated ferric oxide in the technical scheme in the para-para hydrogen conversion.
The invention provides a preparation method of nano hydrated iron oxide, which comprises the following steps: dissolving water-soluble ferric salt and citric acid in water to obtain a mixed solution A; dissolving a precipitator and ethanol in water to obtain a mixed solution B; and dropwise adding the mixed solution B into the mixed solution A to perform hydrothermal reaction to obtain the nano hydrated ferric oxide. The invention firstly prepares the mixed liquor containing water-soluble ferric salt and precipitator, and then the mixed liquor B containing precipitator is dripped into the mixed liquor A containing water-soluble ferric salt for hydrothermal precipitation reaction, so as to obtain the nanoscale hydrated ferric oxide FeOOH, ensure the particle size uniformity and catalytic activity of the catalyst, and have simple preparation process and low cost; citric acid and ethanol are respectively added as dispersing agents in the process of preparing aqueous solution containing water-soluble ferric salt and a precipitating agent and are used for dispersing particles in the hydrothermal reaction process, so that the precipitation speed is controlled, the rapid growth of the particles is avoided, and the nano catalyst with smaller particles is obtained. The results of the embodiment show that the particle size of the hydrated iron oxide prepared by the preparation method provided by the invention is 15-25 nm; the catalyst was used for catalytic conversion of para-hydrogen, the concentration of para-hydrogen was 49.7%, and the conversion rate was 99.3%.
Drawings
FIG. 1 is an XRD pattern of nano iron oxide hydrate prepared in examples 1 to 7 of the present invention;
figure 2 is a schematic diagram of the apparatus employed for para-hydrogen conversion.
Detailed Description
The invention provides a preparation method of nano hydrated iron oxide, which comprises the following steps:
(1) dissolving water-soluble ferric salt and citric acid in water to obtain a mixed solution A;
(2) dissolving a precipitator and ethanol in water to obtain a mixed solution B;
(3) dropwise adding the mixed solution B obtained in the step (2) into the mixed solution A obtained in the step (1) to perform hydrothermal reaction to obtain nano hydrated iron oxide;
the steps (1) and (2) are not in sequence.
According to the invention, water-soluble ferric salt and citric acid are dissolved in water to obtain a mixed solution A. In the invention, the aqueous ferric salt is used as an iron source, the citric acid is used as a dispersing agent to uniformly disperse the water-soluble ferric salt, and the precipitation speed is controlled in the subsequent hydrothermal reaction process to avoid the rapid growth of particles.
In the present invention, the water-soluble iron salt preferably includes one or more of ferric nitrate, ferric chloride and ferric citrate, and more preferably ferric nitrate or ferric chloride.
In the present invention, the water is preferably deionized water.
In the invention, the concentration of the water-soluble iron salt in the mixed solution A is preferably 0.1-2 mol/L, and more preferably 0.5-1.5 mol/L. In the invention, the concentration of citric acid in the mixed solution A is preferably 0.1-1 mol/L, and more preferably 0.3-0.6 mol/L.
The invention dissolves the precipitator and the ethanol in the water to obtain the mixed solution B. In the present invention, the precipitant is used to generate an iron-containing precipitate; the ethanol is used as a dispersing agent to uniformly disperse the precipitator, and the precipitation speed is controlled in the subsequent hydrothermal reaction process to avoid the rapid growth of particles.
In the present invention, the precipitant preferably includes urea or aqueous ammonia, more preferably urea. In the present invention, the mass concentration of the ammonia water is preferably 25 to 28%.
In the present invention, the water is preferably deionized water.
In the invention, the concentration of the precipitant in the mixed solution B is preferably 1-10 mol/L, and more preferably 2-6 mol/L. In the invention, the concentration of the ethanol in the mixed solution B is preferably 1-5 mol/L, and more preferably 2-4 mol/L.
After the mixed solution B and the mixed solution A are obtained, the mixed solution B is dropwise added into the mixed solution A to carry out hydrothermal reaction, and the nano hydrated ferric oxide is obtained. The invention ensures the particle size uniformity and catalytic activity of the catalyst by dripping the mixed solution B into the mixed solution A, if the mixed solution A is dripped into the mixed solution B, the catalyst with non-uniform particle size is obtained, and the catalytic effect of the catalyst is weaker.
In the present invention, the volume ratio of the mixed solution a to the mixed solution B is preferably 2: (1-2), more preferably 2: 1. In the present invention, it is preferable to control the volume ratio of the mixed solution a to the mixed solution B within the above range, which is advantageous for the hydrothermal reaction to proceed sufficiently.
In the invention, the dripping speed is preferably 1-8 mL/min, and more preferably 3-6 mL/min. In the present invention, the rate of the dropwise addition is preferably controlled within the above range, and the mixture liquid B and the mixture liquid a can be sufficiently mixed, thereby making the hydrothermal reaction more sufficient. In the present invention, the apparatus for the dropwise addition is preferably a peristaltic pump.
In the present invention, it is preferable to stir the mixture B while dropping it into the mixture a. In the invention, the stirring speed is preferably 800-1600 r/min, and more preferably 1000-1200 r/min. The stirring device is preferably a magnetic stirrer. In the invention, after the dropwise addition of the mixed solution B is finished, the mixed solution B is preferably continuously stirred for 10-30 min.
In the invention, the temperature of the hydrothermal reaction is preferably 70-200 ℃, and more preferably 90-160 ℃; the time of the hydrothermal reaction is preferably 8-16 h, and more preferably 10-12 h. The invention preferably controls the temperature and time of the hydrothermal reaction within the above range, ensures the hydrothermal reaction to be fully carried out, and is beneficial to obtaining the nano hydrated iron oxide with small particle size and high activity. In the invention, the hydrothermal reaction device is preferably a hydrothermal reaction kettle; the heating device used for the hydrothermal reaction is preferably an oven.
After the hydrothermal reaction is finished, the product after the hydrothermal reaction is preferably separated, washed and dried in sequence to obtain the nano hydrated iron oxide. The operation of the separation, washing and drying is not particularly limited in the present invention, and the separation, washing and drying technical scheme known to those skilled in the art can be adopted. In the present invention, the washing is preferably performed by centrifugal washing; the washing agent used for washing is preferably ethanol and deionized water. The invention preferably removes ions that have not reacted to completion by washing. In the invention, the drying temperature is preferably 90-200 ℃, and more preferably 120-160 ℃; the drying time is preferably 6-16 h, and more preferably 8-12 h.
The invention firstly prepares the mixed liquor containing water-soluble ferric salt and precipitator, and then the mixed liquor B containing precipitator is dripped into the mixed liquor A containing water-soluble ferric salt for hydrothermal reaction, so as to obtain the nanoscale hydrated ferric oxide FeOOH, ensure the particle size uniformity and catalytic activity of the catalyst, and have simple preparation process and low cost; citric acid and ethanol are respectively added as dispersing agents in the process of preparing aqueous solution containing water-soluble ferric salt and a precipitating agent and are used for dispersing particles in the hydrothermal reaction process, so that the precipitation speed is controlled, the rapid growth of the particles is avoided, and the nano catalyst with smaller particles is obtained.
The invention provides the nano hydrated ferric oxide prepared by the preparation method in the technical scheme, wherein the particle size of the nano hydrated ferric oxide is 15-25 nm. The nano hydrated ferric oxide provided by the invention has small particle size and high catalytic activity.
The invention also provides the application of the nano hydrated ferric oxide in the technical scheme in the para-para hydrogen conversion. In the present invention, the temperature of the para-hydrogen conversion is preferably 77K; the hydrogen flow rate for the para-hydrogen conversion is preferably 30-90 mL/min.
The device adopted by the normal-para-hydrogen conversion is shown in figure 2, the nano hydrated ferric oxide is placed in a converter, then a dewar bottle is filled with liquid nitrogen, the converter is placed in the dewar bottle filled with the liquid nitrogen, and high-purity hydrogen after dehydration and deoxidation is introduced after the temperature displayed by a temperature probe in a temperature sensor is the liquid nitrogen temperature, so that the normal-para-hydrogen conversion is carried out.
The nano hydrated ferric oxide prepared by the preparation method provided by the invention is used for catalytic conversion of para-hydrogen, and the efficient conversion of the ortho-hydrogen to the para-hydrogen is realized.
The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
(1) Dissolving 20.2g of ferric nitrate and 10.5g of citric acid in 100mL of deionized water to obtain Fe3+The concentration of the A mixed solution is 0.5mol/L and the concentration of the citric acid is 0.5 mol/L;
(2) dissolving 12.0g of urea and 2.3g of ethanol in 50mL of deionized water to obtain a mixed solution B with the urea concentration of 4mol/L and the ethanol concentration of 1 mol/L;
(3) dropwise adding the mixed liquor B obtained in the step (2) into the mixed liquor A obtained in the step (1) by using a peristaltic pump at a speed of 1mL/min, stirring by using a magnetic stirrer at a speed of 1000r/min while dropwise adding the mixed liquor B, and continuously stirring for 10min after the mixed liquor B is completely dropwise added to obtain a mixed liquor C, wherein the volume ratio of the mixed liquor A to the mixed liquor B is 2: 1;
(4) and (3) pouring the mixed solution C obtained in the step (3) into a hydrothermal reaction kettle, then putting the hydrothermal reaction kettle into an oven, reacting for 14 hours at 110 ℃, naturally cooling to room temperature after the reaction is finished, carrying out solid-liquid separation to obtain a precipitate, then putting the precipitate into a centrifugal tube, firstly adding ethanol, centrifugally washing for three times, then centrifugally washing with deionized water to neutrality, drying for 16 hours at 90 ℃, and naturally cooling to room temperature to obtain the nano hydrated iron oxide.
XRD detection is carried out on the nano iron oxide hydrate prepared in the embodiment, and the obtained XRD pattern is shown in figure 1. As can be seen from fig. 1, the product prepared in this example is hydrated iron oxide, and the average particle size calculated from the XRD spectrum by the scherrer equation is 24 nm.
Example 2
(1) Dissolving 4.0g of ferric nitrate and 4.2g of citric acid in 100mL of deionized water to obtain Fe3+The concentration of the A mixed solution is 0.1mol/L and the concentration of the citric acid is 0.2 mol/L;
(2) dissolving 3.0g of urea and 9.2g of ethanol in 50mL of deionized water to obtain a mixed solution B with 1mol/L of urea and 4mol/L of ethanol:
(3) dropwise adding the mixed liquor B obtained in the step (2) into the mixed liquor A obtained in the step (1) by using a peristaltic pump at a speed of 8mL/min, stirring by using a magnetic stirrer at a speed of 800r/min while dropwise adding the mixed liquor B, and continuously stirring for 15min after the mixed liquor B is completely dripped to obtain a mixed liquor C, wherein the volume ratio of the mixed liquor A to the mixed liquor B is 2: 1;
(4) and (3) pouring the mixed solution C obtained in the step (3) into a hydrothermal kettle, then putting the hydrothermal kettle into an oven, reacting for 16h at 100 ℃, naturally cooling to room temperature after the reaction is finished, carrying out solid-liquid separation to obtain a precipitate, then putting the precipitate into a centrifuge tube, firstly adding ethanol, centrifugally washing for three times, then centrifugally washing with deionized water to neutrality, drying for 8h at 120 ℃, and naturally cooling to room temperature to obtain the nano hydrated iron oxide.
XRD detection is carried out on the nano iron oxide hydrate prepared in the embodiment, and the obtained XRD pattern is shown in figure 1. As can be seen from fig. 1, the product prepared in this example was hydrated iron oxide, and the average particle size was 17nm as calculated from the XRD spectrum by the scherrer equation.
Example 3
(1) 40.4g of ferric nitrate and 21g of citric acid are dissolved in 100mL of deionized water to obtain Fe3+The concentration of the mixed solution A is 1mol/L and the concentration of the citric acid is 1 mol/L;
(2) dissolving 18.3g of 28% ammonia water solution and 11.5g of ethanol in 50mL of deionized water to obtain NH4 +B mixed liquor with the concentration of 6mol/L and the ethanol concentration of 5 mol/L;
(3) dropwise adding the mixed liquor B obtained in the step (2) into the mixed liquor A obtained in the step (1) by using a peristaltic pump at a speed of 8mL/min, stirring by using a magnetic stirrer at a speed of 1200r/min while dropwise adding the mixed liquor B, and continuously stirring for 30min after the mixed liquor B is completely dropwise added to obtain a mixed liquor C, wherein the volume ratio of the mixed liquor A to the mixed liquor B is 2: 1;
(4) and (3) pouring the mixed solution C obtained in the step (3) into a hydrothermal kettle, then putting the hydrothermal kettle into an oven, reacting for 12 hours at 120 ℃, naturally cooling to room temperature after the reaction is finished, carrying out solid-liquid separation to obtain a precipitate, putting the precipitate into a centrifuge tube, firstly adding ethanol, centrifugally washing for three times, then centrifugally washing with deionized water to neutrality, drying for 10 hours at 130 ℃, and naturally cooling to room temperature to obtain the nano hydrated iron oxide.
XRD detection is carried out on the nano iron oxide hydrate prepared in the embodiment, and the obtained XRD pattern is shown in figure 1. As can be seen from fig. 1, the product prepared in this example is hydrated iron oxide, and the average particle size calculated from the XRD spectrum by the scherrer equation is 24 nm.
Example 4
(1) 61g of ferric nitrate and 15.7g of citric acid were dissolved in 100mL of deionized water to obtain Fe3+The concentration of the A mixed solution is 1.5mol/L and the concentration of the citric acid is 0.75 mol/L;
(2) 30.5g of ammonia water solution with the mass concentration of 28% and 5.8g of ethanol are dissolved in 50mL of deionized water to obtain NH4 +B mixed liquor with the concentration of 10mol/L and the ethanol concentration of 2.5 mol/L;
(3) dropwise adding the liquid B obtained in the step (2) into the mixed liquid A obtained in the step (1) by using a peristaltic pump at a speed of 3mL/min, stirring by using a magnetic stirrer at a speed of 1600r/min while dropwise adding the mixed liquid B, and continuously stirring for 20min after the mixed liquid B is completely dropwise added to obtain a mixed liquid C, wherein the volume ratio of the mixed liquid A to the mixed liquid B is 2: 1;
(4) and (3) pouring the mixed solution C obtained in the step (3) into a hydrothermal kettle, then putting the hydrothermal kettle into an oven, reacting for 10 hours at 160 ℃, naturally cooling to room temperature after the reaction is finished, carrying out solid-liquid separation to obtain a precipitate, putting the precipitate into a centrifuge tube, firstly adding ethanol, centrifugally washing for three times, then centrifugally washing with deionized water to neutrality, drying for 8 hours at 150 ℃, and naturally cooling to room temperature to obtain the nano hydrated iron oxide.
XRD detection is carried out on the nano iron oxide hydrate prepared in the embodiment, and the obtained XRD pattern is shown in figure 1. As can be seen from fig. 1, the product prepared in this example is hydrated iron oxide, and the average particle size is 25nm as calculated by the scherrer equation from the XRD spectrum.
Example 5
(1) Dissolving 19g of ferric chloride and 12.7g of citric acid in 100mL of deionized water to obtain Fe3+The concentration of the A mixed solution is 0.7mol/L and the concentration of the citric acid is 0.6 mol/L;
(2) dissolving 36.0g of urea and 18.5g of ethanol in 100mL of deionized water to obtain a mixed solution B with the urea concentration of 6mol/L and the ethanol concentration of 4 mol/L;
(3) dropwise adding the mixed liquor B obtained in the step (2) into the mixed liquor A obtained in the step (1) by using a peristaltic pump at the speed of 2mL/min, stirring by using a magnetic stirrer at the speed of 1200r/min while dropwise adding the mixed liquor B, and continuously stirring for 15min after the mixed liquor B is completely dropwise added to obtain a mixed liquor C, wherein the volume ratio of the mixed liquor A to the mixed liquor B is 2: 2;
(4) and (3) pouring the mixed solution C obtained in the step (3) into a hydrothermal kettle, then putting the hydrothermal kettle into an oven, reacting for 8 hours at 200 ℃, naturally cooling to room temperature after the reaction is finished, carrying out solid-liquid separation to obtain a precipitate, putting the precipitate into a centrifuge tube, firstly adding ethanol, centrifugally washing for three times, then centrifugally washing with deionized water to neutrality, continuously drying for 6 hours at 200 ℃, and naturally cooling to room temperature to obtain the nano hydrated iron oxide.
XRD detection is carried out on the nano iron oxide hydrate prepared in the embodiment, and the obtained XRD pattern is shown in figure 1. As can be seen from fig. 1, the product prepared in this example is hydrated iron oxide, and the average particle size is 20nm as calculated by the scherrer equation from the XRD spectrum.
Example 6
(1) Dissolving 24.5g of ferric citrate and 6.3g of citric acid in 100mL of deionized water to obtain Fe3+The concentration of the mixed solution A is 1mol/L and the concentration of the citric acid is 0.3 mol/L;
(2) dissolving 30.0g of urea and 4.6g of ethanol in 100mL of deionized water to obtain a mixed solution B with the urea concentration of 5mol/L and the ethanol concentration of 1 mol/L;
(3) dropwise adding the mixed liquor B obtained in the step (2) into the mixed liquor A obtained in the step (1) by using a peristaltic pump at the speed of 6mL/min, stirring by using a magnetic stirrer at the speed of 1000r/min while dropwise adding the mixed liquor B, and continuously stirring for 20min after the mixed liquor B is completely dropwise added to obtain a mixed liquor C, wherein the volume ratio of the mixed liquor A to the mixed liquor B is 2: 2;
(4) and (3) pouring the mixed solution C obtained in the step (3) into a hydrothermal kettle, then putting the hydrothermal kettle into an oven, reacting for 15h at 90 ℃, naturally cooling to room temperature after the reaction is finished, carrying out solid-liquid separation to obtain a precipitate, putting the precipitate into a centrifugal tube, firstly adding ethanol, centrifugally washing for three times, then centrifugally washing with deionized water to neutrality, continuously drying for 12h at 110 ℃, and naturally cooling to room temperature to obtain the nano hydrated iron oxide.
XRD detection is carried out on the nano iron oxide hydrate prepared in the embodiment, and the obtained XRD pattern is shown in figure 1. As can be seen from fig. 1, the product prepared in this example is hydrated iron oxide, and the average particle size calculated from the XRD spectrum by the scherrer equation is 18 nm.
Example 7
(1) Dissolving 13.5g of ferric chloride and 21g of citric acid in 100mL of deionized water to obtain Fe3+The concentration of the A mixed solution is 0.5mol/L and the concentration of the citric acid is 11 mol/L;
(2) dissolving 12.2g of ammonia water solution with the mass concentration of 28% and 4.6g of ethanol in 100mL of deionized water to obtain NH4 +B mixed liquor with the concentration of 2mol/L and the ethanol concentration of 1 mol/L;
(3) dropwise adding the mixed liquor B obtained in the step (2) into the mixed liquor A obtained in the step (1) by using a peristaltic pump at a speed of 5mL/min, stirring by using a magnetic stirrer at a speed of 1200r/min while dropwise adding the mixed liquor B, and continuously stirring for 30min after the mixed liquor B is completely dropwise added to obtain a mixed liquor C, wherein the volume ratio of the mixed liquor A to the mixed liquor B is 2: 2;
(4) and (3) pouring the mixed solution C obtained in the step (3) into a hydrothermal kettle, then putting the hydrothermal kettle into an oven, reacting for 12 hours at 150 ℃, naturally cooling to room temperature after the reaction is finished, carrying out solid-liquid separation to obtain a precipitate, putting the precipitate into a centrifuge tube, firstly adding ethanol, centrifugally washing for three times, then centrifugally washing with deionized water to neutrality, continuously drying for 12 hours at 120 ℃, and naturally cooling to room temperature to obtain the nano hydrated iron oxide.
XRD detection is carried out on the nano iron oxide hydrate prepared in the embodiment, and the obtained XRD pattern is shown in figure 1. As can be seen from fig. 1, the product prepared in this example is hydrated iron oxide, and the average particle size calculated from the XRD spectrum by the scherrer equation is 21 nm.
Application example
Putting 3g of the nano hydrated iron oxide prepared in the embodiment 1-7 into a converter, vacuumizing and reducing for 6h at 130 ℃, filling liquid nitrogen in a dewar bottle, putting the converter into the dewar bottle filled with the liquid nitrogen, introducing high-purity hydrogen subjected to dehydration and deoxidation into the dewar bottle when the temperature displayed by a temperature probe is the liquid nitrogen temperature, performing normal-para-hydrogen conversion, measuring the flow rate of hydrogen by using a rotameter, finally analyzing the content of para-hydrogen in a gas chromatograph, and calculating the normal-para-hydrogen conversion rate, wherein the results are shown in table 1, and the hydrogen flow rates are respectively 30, 60 and 90 mL/min.
TABLE 1 conversion of ortho-para-Hydrogen for the nano-hydrated iron oxides prepared in examples 1-7
As can be seen from Table 1, the nano hydrated iron oxide prepared by the method has high reactivity on the catalytic conversion of the para-hydrogen, and the concentration of the para-hydrogen is more than 48 percent (the theoretical equilibrium concentration of the para-hydrogen is 49.87 percent at 77K) at the temperature of 77K, and the conversion rate is more than 95 percent.
The embodiment shows that the nano hydrated ferric oxide prepared by the preparation method provided by the invention has small particle size and high activity, and when the nano hydrated ferric oxide is used for para-para hydrogen catalytic conversion, the concentration of para-hydrogen is more than 48%, and the conversion rate is more than 95%; moreover, the preparation method provided by the invention is simple in process and low in cost.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A preparation method of nano hydrated iron oxide comprises the following steps:
(1) dissolving water-soluble ferric salt and citric acid in water to obtain a mixed solution A;
(2) dissolving a precipitator and ethanol in water to obtain a mixed solution B;
(3) dropwise adding the mixed solution B obtained in the step (2) into the mixed solution A obtained in the step (1) to perform hydrothermal reaction to obtain nano hydrated iron oxide;
the steps (1) and (2) are not in sequence.
2. The preparation method according to claim 1, wherein the water-soluble ferric salt in step (1) comprises one or more of ferric nitrate, ferric chloride and ferric citrate.
3. The method according to claim 1, wherein the concentration of the water-soluble iron salt in the mixed solution A in the step (1) is 0.1 to 2mol/L, and the concentration of the citric acid is 0.1 to 1 mol/L.
4. The method according to claim 1, wherein the precipitant in the step (2) comprises urea or ammonia water.
5. The method according to claim 1, wherein the concentration of the precipitant and the concentration of the ethanol in the mixture B in the step (2) are 1 to 10mol/L and 1 to 5mol/L, respectively.
6. The method according to claim 1, wherein the volume ratio of the mixed solution A to the mixed solution B in the step (3) is 2: (1-2).
7. The method according to claim 1 or 6, wherein the dropping speed in the step (3) is 1 to 8 mL/min.
8. The preparation method according to claim 1, wherein the temperature of the hydrothermal reaction in the step (3) is 70-200 ℃ and the time of the hydrothermal reaction is 8-16 h.
9. The nano hydrated iron oxide prepared by the preparation method of any one of claims 1 to 8, wherein the nano hydrated iron oxide has a particle size of 15 to 25 nm.
10. Use of the nano-iron oxide hydrate of claim 9 in para-hydrogen conversion.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101633522A (en) * | 2009-08-25 | 2010-01-27 | 陕西科技大学 | Method for preparing alpha-iron oxide nano-powder |
| CN103274478A (en) * | 2013-06-15 | 2013-09-04 | 厦门大学 | Method for preparing water-soluble ferroferric oxide nano particle |
| US20130251624A1 (en) * | 2012-03-20 | 2013-09-26 | Korea University Research And Business Foundation | Method for preparation of hematite iron oxide with different nanostructures and hematite iron oxide prepared thereby |
| CN104445427A (en) * | 2014-12-04 | 2015-03-25 | 浙江大学 | Alpha-FeOOH nano sheet and preparation method thereof |
| US20170287516A1 (en) * | 2014-09-24 | 2017-10-05 | Dowa Electronics Materials Co., Ltd. | Iron-based oxide magnetic particle powder and method for producing iron-based oxide magnetic particle powder |
| CN110451579A (en) * | 2019-08-20 | 2019-11-15 | 临沂大学 | A kind of dispersion Fe2O3Preparation method |
| CN111661878A (en) * | 2019-03-05 | 2020-09-15 | 中国石油天然气股份有限公司 | Preparation method of nano alpha-iron oxide hydroxide |
| CN113797928A (en) * | 2021-11-16 | 2021-12-17 | 北京大臻科技有限公司 | Ortho-para hydrogen conversion catalyst for liquid hydrogen conversion and preparation method thereof |
| CN113853356A (en) * | 2019-05-24 | 2021-12-28 | 日铁矿业株式会社 | Method for producing cobalt ferrite particles and cobalt ferrite particles produced thereby |
-
2022
- 2022-01-12 CN CN202210029537.5A patent/CN114314677A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101633522A (en) * | 2009-08-25 | 2010-01-27 | 陕西科技大学 | Method for preparing alpha-iron oxide nano-powder |
| US20130251624A1 (en) * | 2012-03-20 | 2013-09-26 | Korea University Research And Business Foundation | Method for preparation of hematite iron oxide with different nanostructures and hematite iron oxide prepared thereby |
| CN103274478A (en) * | 2013-06-15 | 2013-09-04 | 厦门大学 | Method for preparing water-soluble ferroferric oxide nano particle |
| US20170287516A1 (en) * | 2014-09-24 | 2017-10-05 | Dowa Electronics Materials Co., Ltd. | Iron-based oxide magnetic particle powder and method for producing iron-based oxide magnetic particle powder |
| CN104445427A (en) * | 2014-12-04 | 2015-03-25 | 浙江大学 | Alpha-FeOOH nano sheet and preparation method thereof |
| CN111661878A (en) * | 2019-03-05 | 2020-09-15 | 中国石油天然气股份有限公司 | Preparation method of nano alpha-iron oxide hydroxide |
| CN113853356A (en) * | 2019-05-24 | 2021-12-28 | 日铁矿业株式会社 | Method for producing cobalt ferrite particles and cobalt ferrite particles produced thereby |
| CN110451579A (en) * | 2019-08-20 | 2019-11-15 | 临沂大学 | A kind of dispersion Fe2O3Preparation method |
| CN113797928A (en) * | 2021-11-16 | 2021-12-17 | 北京大臻科技有限公司 | Ortho-para hydrogen conversion catalyst for liquid hydrogen conversion and preparation method thereof |
Non-Patent Citations (3)
| Title |
|---|
| BAOPING JIA ET AL.: "Selected-Control Synthesis and the Phase Transition of Fe3O4 and α-FeOOH in Ethanol/Water Media", 《J. AM. CERAM. SOC.》 * |
| 周自成等: "聚乙二醇、EDTA和柠檬酸对氧化沉淀法制备纳米Mn_3O_4晶粒尺寸的影响", 《沧州师范学院学报》 * |
| 金建等: "纳米α-FeOOH的制备及在煤-油共炼中的催化性能", 《石油学报(石油加工)》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115155583A (en) * | 2022-06-21 | 2022-10-11 | 中盐金坛盐化有限责任公司 | Electrically supported ortho-para hydrogen conversion catalyst and preparation method thereof |
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