Catalyst for hydrogen production by ammonia decomposition and method for preparing the same

Abstract

The application relates to the technical field of catalysts, and discloses a nickel-based hydrogen production catalyst for ammonia decomposition and a preparation method thereof, which comprises the following steps: mixing nickel nitrate, magnesium nitrate, aluminum nitrate and lanthanum nitrate, and dissolving the mixture in water to prepare a nickel-magnesium-aluminum-lanthanum mixed salt solution; the solution is added drop by drop into a sodium carbonate aqueous solution, and a sodium hydroxide solution is added drop by drop to maintain pH=9.5-10.5, and a suspension is obtained; the suspension is aged, filtered, washed and dried to obtain a nickel-magnesium-aluminum-lanthanum hydrotalcite precursor; the nickel-magnesium-aluminum-lanthanum hydrotalcite precursor is calcined in an air atmosphere, and grinding, tabletting and sieving are carried out to obtain a Ni 20 Mg 55 Al 25‑x La x catalyst; the Ni 20 Mg 55 Al 25‑x La x catalyst is reduced in an ammonia atmosphere to obtain a high-dispersion La2O3-Ni / Mg(Al)O catalyst. The catalyst activity of the catalyst is effectively improved, and the catalyst shows good sintering resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to a catalyst for producing hydrogen by decomposing ammonia and a preparation method thereof. Background Art

[0002] Ammonia decomposition is an endothermic reaction. Thermodynamic analysis shows that at ambient pressure and relatively low temperatures, ammonia conversion is very low, requiring very high temperatures to achieve complete ammonia conversion. Therefore, developing low-temperature, high-efficiency catalysts is a top priority for hydrogen production from ammonia decomposition.

[0003] Currently, ammonia decomposition catalysts can be categorized as precious metal catalysts, transition metal catalysts, bimetallic catalysts, metal nitride and carbide catalysts, and composite metal catalysts. Among these, transition metal catalysts are abundant and exhibit excellent high-temperature resistance. Transition metal catalysts can be further categorized as nickel-based, iron-based, cobalt-based, and molybdenum-based, with nickel-based catalysts being the most commonly used. The transition metal Ni is one of the most commonly used elements in metal catalysts. Although nickel-based catalysts are not as active as precious metal catalysts, they are considered to have the best performance for NH3 decomposition among non-precious metal catalysts.

[0004] Traditional synthesis methods such as co-precipitation, deposition-precipitation, and impregnation are widely used to prepare nickel-based catalysts. However, these methods often suffer from the problem of thermal sintering of nickel nanoparticles at high reaction temperatures, resulting in low stability. Nickel-based catalysts hold great promise as catalysts for hydrogen production from ammonia decomposition, but they still suffer from the drawbacks of large nickel particle size and sintering at high temperatures. Therefore, developing nickel-based catalysts for hydrogen production from ammonia decomposition with high activity and stability at low temperatures to improve the efficiency of hydrogen production from ammonia decomposition is of great practical significance. Summary of the Invention

[0005] In view of this, the present invention proposes a catalyst for hydrogen production by decomposing ammonia and a preparation method thereof, comprising the following steps:

[0006] S1: nickel nitrate, magnesium nitrate, aluminum nitrate and lanthanum nitrate are mixed and dissolved in water to prepare a nickel-magnesium-aluminum-lanthanum mixed salt solution;

[0007] S2: adding the nickel-magnesium-aluminum-lanthanum mixed salt solution dropwise to the sodium carbonate aqueous solution, while adding sodium hydroxide solution dropwise to maintain the pH value at 9.5-10.5, and obtaining a suspension;

[0008] S3: allowing the suspension to stand for aging, filtering, washing, and drying to obtain a nickel-magnesium-aluminum-lanthanum hydrotalcite precursor;

[0009] S4: calcining the nickel-magnesium-aluminum-lanthanum hydrotalcite precursor in air atmosphere, grinding, tableting, and sieving to obtain Ni 20 Mg 55 A l25-x La x catalyst;

[0010] S5: The Ni 20 Mg 55 A l 25-x La x The catalyst was reduced in an ammonia atmosphere to obtain a highly dispersed La2O3-Ni / Mg(Al)O catalyst.

[0011] Furthermore, in step S1, the molar ratio of each metal cation in the nickel-magnesium-aluminum-lanthanum mixed salt solution is nickel ion: magnesium ion: aluminum ion: lanthanum ion = 20:55: (15-22.5): (2.5-10).

[0012] Furthermore, in step S2, the concentration of the sodium hydroxide solution is 2 mol·L -1 .

[0013] Furthermore, in step S3, the static aging time is 22-26 hours.

[0014] Furthermore, in step S3, the washing is performed using deionized water.

[0015] Furthermore, in step S4, the calcination is carried out from room temperature at 3°C·min -1 The temperature was raised to 500 °C at a rate of 100 °C and then kept constant for 5 h.

[0016] Furthermore, in step S4, the mesh size of the sieving is 30-60 meshes.

[0017] Furthermore, in step S5, the reduction is carried out from room temperature at 10°C·min -1 The temperature was raised to 750 °C at a rate of 0.1 °C and then kept constant for 30 min.

[0018] On the other hand, the present invention also provides a catalyst for producing hydrogen by decomposing ammonia, which is prepared by the above method.

[0019] Furthermore, the operating temperature of the catalyst for producing hydrogen by decomposing ammonia is 350-600°C.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The metal ions in the nickel-magnesium-aluminum-lanthanum hydrotalcite precursor prepared by the present invention are uniformly dispersed in the brucite-like layer. The nickel-magnesium-aluminum-lanthanum hydrotalcite is calcined at 500°C to obtain Ni 20 Mg 55 A l 25-x La x Catalyst, wherein Ni 2+ and Al3 + It enters the MgO lattice to form Mg(Ni,Al)O solid solution, and La2O3 is highly dispersed. After ammonia reduction, metallic Ni is evenly dispersed on the surface of Mg(Al)O. La 3+ The catalyst is highly dispersed and has a synergistic effect with Ni metal, effectively improving the catalytic activity of the catalyst. The catalyst exhibits excellent ammonia decomposition catalytic activity and good anti-sintering ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0023] Figure 1 This is the X-ray powder diffraction spectrum of the hydrotalcite precursor of Example 1 of the present invention;

[0024] Figure 2 This is the X-ray powder diffraction spectrum of the calcined sample of Example 1 of the present invention;

[0025] Figure 3 is the X-ray powder diffraction spectrum of the reduction catalyst of Example 1 of the present invention;

[0026] Figure 4 This is the X-ray powder diffraction spectrum of the hydrotalcite precursor of Example 2 of the present invention;

[0027] Figure 5 This is the X-ray powder diffraction spectrum of the calcined sample of Example 2 of the present invention;

[0028] Figure 6 This is the X-ray powder diffraction spectrum of the reduction catalyst of Example 2 of the present invention;

[0029] Figure 7 Element distribution diagram of the reduction catalyst of Example 2 of the present invention;

[0030] Figure 8 This is a HAADF-STEM image of the reduced catalyst of Example 2 of the present invention;

[0031] Figure 9 This is the X-ray powder diffraction spectrum of the hydrotalcite precursor of Example 3 of the present invention;

[0032] Figure 10 This is the X-ray powder diffraction spectrum of the calcined sample of Example 3 of the present invention;

[0033] Figure 11This is the X-ray powder diffraction spectrum of the reduction catalyst of Example 3 of the present invention;

[0034] Figure 12 This is the X-ray powder diffraction spectrum of the hydrotalcite precursor of Example 4 of the present invention;

[0035] Figure 13 This is the X-ray powder diffraction spectrum of the calcined sample of Example 4 of the present invention;

[0036] Figure 14 This is the X-ray powder diffraction spectrum of the reduction catalyst of Example 4 of the present invention;

[0037] Figure 15 This is the X-ray powder diffraction spectrum of the hydrotalcite precursor of Comparative Example 1 of the present invention;

[0038] Figure 16 This is the X-ray powder diffraction spectrum of the calcined sample of Comparative Example 1 of the present invention;

[0039] Figure 17 This is the X-ray powder diffraction spectrum of the reduced catalyst of Comparative Example 1 of the present invention;

[0040] Figure 18 The ammonia decomposition activity test results of Examples 1-4 of the present invention and Comparative Example 1 are shown;

[0041] Figure 19 The results of ammonia decomposition activity of the catalyst of Example 2 of the present invention at different space velocities are shown;

[0042] Figure 20 These are the stability test results of the ammonia decomposition reaction of the catalyst in Example 2 of the present invention. DETAILED DESCRIPTION

[0043] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, unless there is a conflict, the embodiments of the present disclosure and the features described in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0044] The test conditions for the ammonia decomposition reaction activity at different space velocities in the embodiments of the present invention are:

[0045] (i) The raw gas composition is pure NH3, with a flow rate of 25 mL min -1 A fixed bed quartz reactor was used, 300 mg of catalyst was used, and the space velocity was 5000 mL·g -1 ·h-1 ;

[0046] (ii) The raw gas composition is pure NH3, with a flow rate of 25 mL min -1 A fixed bed quartz reactor was used, 150 mg of catalyst was used, and the space velocity was 10000 mL·g -1 ·h -1 ;

[0047] (iii) The raw gas composition is pure NH3, with a flow rate of 25 mL min -1 A fixed bed quartz reactor was used, 50 mg of catalyst was used, and the space velocity was 30000 mL·g -1 ·h -1 .

[0048] The stability evaluation conditions of the ammonia decomposition hydrogen production reaction are as follows: a fixed bed quartz reactor is used, 50 mg of catalyst is used, the feed gas composition is pure NH3, and the flow rate is 25 mL·min -1 , space velocity 30000 mL·g -1 ·h -1 , react at 550°C for 100 hours.

[0049] Example 1

[0050] 3.3138g Ni(NO3)2·6H2O, 8.0354gMg(NO3)2·6H2O, 4.8092gAl(NO3)3·9H2O and 0.6168gLa(NO3)3·6H2O were dissolved in 200mL of deionized water to prepare a mixed metal salt solution. At the same time, 0.7549gNa2CO3 was weighed and dissolved in 100mL of deionized water. The Na2CO3 solution was used as the base solution. 8.0000gNaOH was weighed and dissolved in 100mL of deionized water to prepare a 2mol / L NaOH solution as the regulating solution. The mixed metal salt solution prepared above was added dropwise to the Na2CO3 solution, and NaOH solution was added dropwise to maintain the solution pH = 10±0.5. After aging the suspension at room temperature for 24h, it was washed with deionized water until neutral, and then dried at 100℃ overnight to obtain Ni 20 Mg 55 A l 22.5 La 2.5 -HT hydrotalcite precursor. The dried precursor was placed in a muffle furnace and calcined at 500℃ for 5h with a heating rate of 3℃·min -1 , get the Ni 20 Mg 55 A l 22.5 La 2.5 Catalyst; Ni 20 Mg 55 A l22.5 La 2.5 The catalyst was ground, tableted, and sieved to obtain 30-60 mesh particles. Then, the catalyst was reduced at a temperature of 750°C and a heating rate of 10°C / min in an ammonia atmosphere. -1 , keep for 30 minutes, and obtain the reduced Ni 20 Mg 55 A l 22.5 La 2.5 catalyst.

[0051] The precursor, calcined sample and reduced sample were characterized by X-ray powder diffraction. Figure 1 、 2 , 3. The XRD spectrum of the precursor only shows characteristic diffraction peaks of hydrotalcite-like materials. The XRD spectrum of the calcined sample only shows diffraction peaks of the Mg(Ni,Al)O solid solution, with no diffraction peaks of lanthanum oxide, indicating a high dispersion of La. The XRD spectrum of the reduced sample shows characteristic diffraction peaks of Mg(Ni,Al)O and metallic Ni. The average crystallite size of the metallic Ni particles calculated using the Scherrer equation is 5.1 nm.

[0052] Example 2

[0053] 3.1465g Ni(NO3)2·6H2O, 7.6299gMg(NO3)2·6H2O, 4.0592gAl(NO3)3·9H2O and 1.1714gLa(NO3)3·6H2O were dissolved in 200mL of deionized water to prepare a mixed metal salt solution. At the same time, 0.7168gNa2CO3 was weighed and dissolved in 100mL of deionized water. The Na2CO3 solution was used as the base liquid. 8.0000gNaOH was weighed and dissolved in 100mL of deionized water to prepare a 2mol / L NaOH solution as the regulating liquid. The mixed metal salt solution prepared above was added dropwise to the Na2CO3 solution, and NaOH solution was added dropwise to maintain the solution pH = 10±0.5. After aging the suspension at room temperature for 24h, it was washed with deionized water until neutral, and then dried at 100℃ overnight to obtain Ni 20 Mg 55 A l 20 La5-HT hydrotalcite precursor. The dried precursor was placed in a muffle furnace and calcined at 500℃ for 5h with a heating rate of 3℃·min -1 , get the Ni 20 Mg 55 A l 20 La5 catalyst; Ni 20 Mg 55 A l 20The La5 catalyst was ground, pressed and sieved to obtain 30-60 mesh particles. Then, the catalyst was reduced at a temperature of 750°C and a heating rate of 10°C / min under an ammonia atmosphere. -1 , keep for 30 minutes, and obtain the reduced Ni 20 Mg 55 A l 20 La5 catalyst.

[0054] The precursor, calcined sample and reduced sample were characterized by X-ray powder diffraction. Figure 4 、 5 , 6. The XRD spectrum of the precursor only shows characteristic diffraction peaks of hydrotalcite-like materials. The XRD spectrum of the calcined sample only shows diffraction peaks of the Mg(Ni,Al)O solid solution, with no diffraction peaks of lanthanum oxide, indicating a high dispersion of La. The XRD spectrum of the reduced sample shows characteristic diffraction peaks of Mg(Ni,Al)O and metallic Ni. The average crystallite size of the metallic Ni particles calculated using the Scherrer equation is 6.4 nm.

[0055] The element distribution of the reduced samples was analyzed by X-ray energy dispersive spectroscopy, such as Figure 7 As shown, uniform distribution of Ni, Mg, Al, La and O can be observed. Figure 8 This is the HAADF-STEM image, and the average particle size of metal Ni is calculated to be 8.9 nm.

[0056] Example 3

[0057] Dissolve 2.9954g Ni(NO3)2·6H2O, 7.2634gMg(NO3)2·6H2O, 3.3811gAl(NO3)3·9H2O and 1.6726gLa(NO3)3·6H2O in 200mL of deionized water to prepare a mixed metal salt solution. At the same time, weigh 0.6824gNa2CO3 and dissolve it in 100mL of deionized water. The Na2CO3 solution is used as the base liquid. Weigh 8.0000gNaOH and dissolve it in 100mL of deionized water to prepare a 2mol / L NaOH solution as the regulating liquid. Add the above-prepared mixed metal salt solution dropwise to the Na2CO3 solution, and at the same time add NaOH solution dropwise to maintain the solution pH = 10±0.5. After aging the suspension at room temperature for 24h, wash it with deionized water until it is neutral, and then dry it at 100℃ overnight to obtain Ni 20 Mg 55 A l 17.5 La 7.5 -HT hydrotalcite precursor. The dried precursor was placed in a muffle furnace and calcined at 500℃ for 5h with a heating rate of 3℃·min -1, get the Ni 20 Mg 55 A l 17.5 La 7.5 Catalyst; Ni 20 Mg 55 A l 17.5 La 7.5 The catalyst was ground, tableted, and sieved to obtain 30-60 mesh particles. Then, the catalyst was reduced at a temperature of 750°C and a heating rate of 10°C / min in an ammonia atmosphere. -1 , keep for 30 minutes, and obtain the reduced Ni 20 Mg 55 A l 17.5 La 7.5 catalyst.

[0058] The precursor, calcined sample and reduced sample were characterized by X-ray powder diffraction. Figure 9 、 10 , 11. The XRD spectrum of the precursor only shows characteristic diffraction peaks of hydrotalcite-like materials. The XRD spectrum of the calcined sample only shows diffraction peaks of the Mg(Ni,Al)O solid solution, with no diffraction peaks of lanthanum oxide, indicating a high dispersion of La. The XRD spectrum of the reduced sample shows characteristic diffraction peaks of Mg(Ni,Al)O and metallic Ni. The average crystallite size of the metallic Ni particles calculated using the Scherrer equation is 10.1 nm.

[0059] Example 4

[0060] Dissolve 2.8581g Ni(NO3)2·6H2O, 6.9305gMg(NO3)2·6H2O, 2.7653gAl(NO3)3·9H2O and 2.1280gLa(NO3)3·6H2O in 200mL of deionized water to prepare a mixed metal salt solution. At the same time, weigh 0.0.6511gNa2CO3 and dissolve it in 100mL of deionized water. The Na2CO3 solution is used as the base liquid. Weigh 8.0000gNaOH and dissolve it in 100mL of deionized water to prepare a 2mol / L NaOH solution as the regulating liquid. Add the above-prepared mixed metal salt solution dropwise to the Na2CO3 solution, and at the same time add NaOH solution dropwise to maintain the solution pH = 10±0.5. After aging the suspension at room temperature for 24h, wash it with deionized water until it is neutral, and then dry it at 100℃ overnight to obtain Ni 20 Mg 55 A l 15 La 10 -HT hydrotalcite precursor. The dried precursor was placed in a muffle furnace and calcined at 500℃ for 5h with a heating rate of 3℃·min-1 , get the Ni 20 Mg 55 A l 15 La 10 Catalyst; Ni 20 Mg 55 A l 15 La 10 The catalyst was ground, tableted, and sieved to obtain 30-60 mesh particles. Then, the catalyst was reduced at a temperature of 750°C and a heating rate of 10°C / min in an ammonia atmosphere. -1 , keep for 30 minutes, and obtain the reduced Ni 20 Mg 55 A l 15 La 10 catalyst.

[0061] The precursor, calcined sample and reduced sample were characterized by X-ray powder diffraction. Figure 12 、 13 , 14. The XRD spectrum of the precursor only shows characteristic diffraction peaks of hydrotalcite-like materials. The XRD spectrum of the calcined sample only shows diffraction peaks of the Mg(Ni,Al)O solid solution, with no diffraction peaks of lanthanum oxide, indicating a high dispersion of La. The XRD spectrum of the reduced sample shows characteristic diffraction peaks of Mg(Ni,Al)O and metallic Ni. The average crystallite size of the metallic Ni particles calculated using the Scherrer equation is 10.1 nm.

[0062] Comparative Example 1

[0063] Dissolve 3.4997g Ni(NO3)2·6H2O, 8.4864gMg(NO3)2·6H2O and 5.6435gAl(NO3)3·9H2O in 200mL of deionized water to prepare a mixed metal salt solution. At the same time, weigh 0.7973gNa2CO3 and dissolve it in 100mL of deionized water. The Na2CO3 solution is used as the base liquid. Weigh 8.0000gNaOH and dissolve it in 100mL of deionized water to prepare a 2mol / L NaOH solution as the regulating liquid. Add the above-prepared mixed metal salt solution dropwise to the Na2CO3 solution, and at the same time add NaOH solution dropwise to maintain the solution pH = 10±0.5. After aging the suspension at room temperature for 24h, wash it with deionized water until it is neutral, and then dry it at 100℃ overnight to obtain Ni 20 Mg 55 A l 25 -HT hydrotalcite precursor. The dried precursor was placed in a muffle furnace and calcined at 500℃ for 5h with a heating rate of 3℃·min -1 , get the Ni 20 Mg55 A l 25 Catalyst; Ni 20 Mg 55 A l 25 The catalyst was ground, tableted, and sieved to obtain 30-60 mesh particles. Then, the catalyst was reduced under an ammonia atmosphere at a temperature of 750°C, a heating rate of 10°C / min, and a holding time of 30 minutes to obtain the reduced Ni 20 Mg 55 A l 25 catalyst.

[0064] The precursor, calcined sample and reduced sample were characterized by X-ray powder diffraction. Figure 15 、 16 , 17. The XRD spectrum of the precursor only shows characteristic diffraction peaks of hydrotalcite-like structures. The XRD spectrum of the calcined sample only shows diffraction peaks of the Mg(Ni,Al)O solid solution. The XRD spectrum of the reduced sample shows characteristic diffraction peaks of Mg(Ni,Al)O and metallic Ni. The average crystallite size of the metallic Ni particles was calculated to be 5.9 nm based on the Scherrer equation.

[0065] The BET specific surface area, pore volume, average pore diameter and average crystal size of metal Ni of the catalysts of Examples 1-4 and Comparative Example 1 are shown in Table 1.

[0066] Table 1 Grain size, BET specific surface area, pore volume, and average pore diameter

[0067]

[0068] In pure ammonia, 30000mL g -1 ·h -1 Under the reaction conditions, the ammonia decomposition activity of the catalysts of Examples 1-4 and Comparative Example 1 was tested as follows: Figure 18 Compared with the catalyst in Comparative Example 1, the catalysts in Examples 1-4 exhibited better catalytic activity, indicating that the addition of La helped to improve catalytic activity. As the La content increased, ammonia conversion first increased and then decreased.

[0069] Ni of Example 2 20 Mg 55 A l 20 The test results of ammonia decomposition activity of La5 catalyst at different space velocities are as follows Figure 19 As shown in Figure 2, as the space velocity decreases, the NH3 conversion rate increases. 20 Mg 55 A l 20 La5 catalyst at a space velocity of 5000 mL·g -1 ·h -1, 500℃ ammonia conversion rate reaches 89.6%. 20 Mg 55 A l 20 The long-term stability test of La5 catalyst was carried out under the conditions of 550℃ and 30000mL·g cat -1 ·h -1 , the results are as follows Figure 20 As shown in the 100h stability test, Ni 20 Mg 55 A l 20 The ammonia conversion of La5 catalyst remained basically unchanged, still maintained at 88%–90%, indicating that the catalyst has good high-temperature stability.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a catalyst for hydrogen production by decomposing ammonia, characterized in that: The following steps are involved: S1: nickel nitrate, magnesium nitrate, aluminum nitrate and lanthanum nitrate are mixed and dissolved in water to prepare a nickel-magnesium-aluminum-lanthanum mixed salt solution; S2: adding the nickel-magnesium-aluminum-lanthanum mixed salt solution dropwise to the sodium carbonate aqueous solution, while adding sodium hydroxide solution dropwise to maintain the pH value at 9.5-10.5, and obtaining a suspension; S3: allowing the suspension to stand for aging, filtering, washing, and drying to obtain a nickel-magnesium-aluminum-lanthanum hydrotalcite precursor; S4: calcining the nickel-magnesium-aluminum-lanthanum hydrotalcite precursor in air atmosphere, grinding, tableting, and sieving to obtain Ni 20 Mg 55 Al 25-x La x catalyst; S5: The Ni 20 Mg 55 Al 25-x La x The catalyst was reduced in an ammonia atmosphere to obtain a highly dispersed La2O3-Ni / Mg(Al)O catalyst; In step S1, the molar ratio of each metal cation in the nickel-magnesium-aluminum-lanthanum mixed salt solution is nickel ion: magnesium ion: aluminum ion: lanthanum ion = 20:55: (15-22.5): (2.5-10).

2. The method for preparing a catalyst for hydrogen production by decomposing ammonia according to claim 1, wherein: In step S2, the concentration of the sodium hydroxide solution is 2 mol·L -1 .

3. The method for preparing a catalyst for hydrogen production by decomposing ammonia according to claim 1, wherein: In step S3, the aging time is 22-26 hours.

4. The method for preparing a catalyst for hydrogen production by decomposing ammonia according to claim 1, wherein: In step S3, the washing is performed using deionized water.

5. The method for preparing a catalyst for hydrogen production by decomposing ammonia according to claim 1, wherein: In step S4, the calcination is carried out from room temperature at 3°C·min -1 The temperature was raised to 500 °C at a rate of 100 °C and then kept constant for 5 h.

6. The method for preparing a catalyst for hydrogen production by decomposing ammonia according to claim 1, characterized in that: In step S4, the mesh size of the sieving is 30-60 meshes.

7. The method for preparing a catalyst for hydrogen production by decomposing ammonia according to claim 6, characterized in that: In step S5, the reduction is carried out from room temperature at 10°C·min -1 The temperature was raised to 750 °C at a rate of 0.1 °C and then kept constant for 30 min.

8. A catalyst for hydrogen production by decomposing ammonia, characterized in that: The catalyst is prepared by the method for preparing the catalyst for hydrogen production by decomposing ammonia according to any one of claims 1 to 7.

9. The catalyst for hydrogen production by decomposing ammonia according to claim 8, characterized in that The operating temperature of the catalyst for hydrogen production by decomposing ammonia is 350-600°C.

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