A kind of MOF derived boron, nitrogen co-doped porous carbon supported iridium catalyst for overall hydrazine decomposition and a preparation method thereof

Abstract

The present application relates to the technical field of porous carbon composite material, and particularly relates to a MOF derived boron and nitrogen co-doped porous carbon supported iridium catalyst for integral hydrazine decomposition and a preparation method thereof. First, 2-methyl imidazole and zinc acetate dihydrate are dispersed in an ethanol solution and are left to stand to obtain ZIF-8. Then, the obtained ZIF-8 is placed in a tube furnace and is calcined at high temperature under a nitrogen atmosphere to obtain porous carbon. Finally, an iridium source, a boron source and a nitrogen source are anchored on the carbon substrate by using a physical adsorption method, and the MOF derived boron and nitrogen co-doped porous carbon supported iridium is obtained by calcining under a nitrogen atmosphere. The catalyst prepared by the present application provides more active sites and good electrical conductivity, and the material exhibits good stability in a high-concentration hydrazine solution. Boron and nitrogen doping causes the generation of holes or p-type characteristics in the valence band of the material, and causes the Fermi level to move downward, further improving the catalytic activity.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalyst technology, and relates to a MOF-derived boron and nitrogen co-doped porous carbon-supported iridium catalyst for monolithic hydrazine decomposition and its preparation method. Background Technology

[0002] Currently, fossil fuels remain the primary source of global energy demand. However, the large-scale use of fossil fuels inevitably leads to severe environmental problems. Water electrolysis is an effective method for obtaining high-purity hydrogen using clean energy sources such as wind and solar power. However, the oxygen evolution reaction at the anode in water electrolysis is kinetically very slow, requiring very high electrolysis potentials and large amounts of expensive catalysts to overcome the significant reaction energy barrier. Therefore, coupling small-molecule electrocatalysts with lower reaction energy barriers, such as methanol, ethanol, formic acid, hydrazine, and urea, can lower the reaction potential at the anode to achieve more efficient hydrogen evolution and simultaneously electrosynthesize high-value products.

[0003] Among various small molecule oxidation reactions, the hydrazine oxidation reaction (HzOR, N2H4 + 4OH) is particularly important. − →N2+4H2O+4e − Hydrazine (−0.33 V vs. RHE) has absolutely no carbon products and less catalyst poisoning, making it an ideal energy-saving alternative for the oxygen evolution reaction (OER). However, hydrazine tends to decompose directly into nitrogen and hydrogen, which reduces the electrochemical utilization rate of hydrazine. Therefore, designing efficient and low-cost monolithic hydrazine decomposition electrocatalysts to improve the electrochemical utilization rate of hydrazine is of great significance for achieving low-energy consumption and high-efficiency hydrogen production.

[0004] In order to improve the hydrazine oxidation performance of catalysts, researchers have generally done the following work in the existing technology: (1) Heterojunction engineering. Shi Jianlin and Cui Xiangzhi of the Shanghai Institute of Ceramics, Chinese Academy of Sciences, loaded a three-dimensional nickel-cobalt phosphide heterojunction on nickel foam and uniformly distributed CoP nanoparticles on NiCoP nanowires through a hydrothermal-phosphating strategy. Hydrazine oxidation under high current density was achieved, but the phosphine gas formed in the catalyst manufacturing process has great harm to the environment, especially to the human heart, respiratory system, kidney, gastrointestinal tract, nervous system and liver. (2) Noble metal catalysis. Xu Ming of Beijing University of Chemical Technology and Wang Yaoyu and Ma Haixia of Northwest University prepared Ru single atoms anchored on sulfur vacancies of WS2 by sulfidation method and constant current deposition method. The sulfur sites showed mild hydrogen-mediated adsorption behavior, and Ru served as the active center for the gradual dehydrogenation of hydrazine in the HzOR process. The prepared single-atom catalyst has 100% atomic utilization, but it cannot provide multiple metal-metal atomic sites, and the atomic aggregation phenomenon caused by the Gibbs free energy of single atoms during the catalytic process has a significant impact on the electrocatalytic performance of the single-atom catalyst. (3). Transition metal modification strategy. Transition metal electrocatalysts have been widely reported to date, including metal nanoparticles, phosphides, oxides, sulfides, and selenides. Although the catalytic activity of transition metal-based materials has been greatly improved, the inherent magnetic susceptibility barrier in corrosive electrolytes may lead to unsatisfactory long-term durability.

[0005] Therefore, providing a MOF-derived boron and nitrogen co-doped porous carbon-supported iridium catalyst for the overall hydrazine decomposition and its preparation method to solve the problems of dosage, activity, and pollution during the preparation of noble metal catalysts is a problem worthy of research. Summary of the Invention

[0006] Therefore, the purpose of this invention is to solve the problems of dosage, activity, and pollution during the preparation of noble metal catalysts. This invention provides a MOF-derived boron and nitrogen co-doped porous carbon-supported iridium catalyst for the overall hydrazine decomposition, addressing these issues. The invention employs a simple physical adsorption-pyrolysis method. Specifically, the first step involves dispersing 2-methylimidazole and zinc acetate dihydrate in an ethanol solution and allowing it to stand to obtain ZIF-8. The second step involves calcining the obtained ZIF-8 at high temperature in a tube furnace under a nitrogen atmosphere to obtain porous carbon. Finally, the porous carbon, iridium trichloride, boric acid, and melamine are mixed and calcined under a nitrogen atmosphere to obtain a MOF-derived boron and nitrogen co-doped porous carbon-supported iridium hydrogen evolution catalyst. The prepared MOF-derived boron and nitrogen co-doped porous carbon-supported iridium catalyst for the overall hydrazine decomposition exhibits a large specific surface area and abundant active sites, demonstrating excellent electrochemical performance in the HzOR catalysis field.

[0007] The objective of this invention is achieved as follows: A method for preparing a MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst for monolithic hydrazine decomposition includes the following steps: Step 1: Weigh 100-500 mg of zinc acetate dihydrate and 985 mg of 2-methylimidazole and dissolve them in 50-90 ml of anhydrous ethanol respectively. After mixing, sonicate for 10-30 min and let stand for 10-24 h to obtain ZIF-8 dispersion. Step 2: Centrifuge, wash and dry the ZIF-8 dispersion obtained in Step 1 to obtain ZIF-8 nanoparticles; Step 3: The ZIF-8 nanoparticles obtained in Step 2 are subjected to carbonization treatment. Under a protective atmosphere, the temperature is increased at a rate of 5℃ / min and held at 950℃ for 2h to obtain nitrogen-doped porous carbon. Step 4: Take 10-20 mg of the nitrogen-doped porous carbon obtained in Step 3, then weigh 5 mg of iridium trichloride, 5-20 mg of boron source, and 5-20 mg of nitrogen source and disperse them in 20-40 ml of water. Stir at 80℃ for 10 h until the reaction is complete, and obtain the precursor solution. Step 5: Centrifuge, wash and dry the precursor solution obtained in Step 4 to obtain precursor particles; Step 6: Place the precursor particles obtained in Step 5 in a tube furnace, and under a protective atmosphere, heat at a rate of 5 °C / min and maintain at 600 °C for 2-4 h to obtain a MOF-derived boron and nitrogen co-doped porous carbon-supported iridium catalyst for the decomposition of hydrazine.

[0008] The solvent used for cleaning in steps 2 and 5 is any one of deionized water, anhydrous ethanol, anhydrous methanol, and isopropanol.

[0009] In steps 2 and 5, the drying temperature is 40-65 ℃ and the drying time is 12-24 h.

[0010] In steps 2 and 5, the centrifugation speed is 6000-8000 rpm and the time is 5-15 min.

[0011] In step 4, the nitrogen source is one or more of the following: urea, melamine, ammonia, cyanamide, and dicyandiamide.

[0012] In step 4, the boron source is one or more of boric acid, boron trioxide, and sodium borohydride.

[0013] The MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst for the overall hydrazine decomposition comprises the following elements by mass fraction: Ir: 2.63-3.93 wt%, B: 0-5.12 wt%, N: 12.66-18.68 wt%, C: 72.63-82.97 wt%, and the BET surface area of ​​the MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst is 900-1100 m². 2 / g.

[0014] The size of the MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst used for the overall hydrazine decomposition is 320-400 nm.

[0015] The active site in the MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst used for the overall hydrazine decomposition is Ir-N3B1. Beneficial effects

[0016] (1) The preparation process of this invention is simple and easy to repeat, and no toxic or harmful waste is generated and flows into the environment during the process; (2) This invention selects elements B (χ=2.04) and N (χ=3.04) with significant differences in electronegativity. The B-binding and electronic structure regulation synergistically prevents Ir-NCs from further agglomerating into nanoparticles (d≈1.68 nm) during pyrolysis. Furthermore, XPS analysis revealed that boron doping in the graphene lattice altered the electronic states of iridium species due to strong metal-supported interactions (SMSI). Due to its high electrochemically active surface area and faster charge transfer capability, the synthesized catalyst exhibits excellent HzOR performance and good electrochemical stability, superior to Ir single-atom catalysts and most reported catalysts. Attached Figure Description

[0017] Figure 1 The images show the X-ray diffraction pattern (a), X-ray photoelectron spectrum (b), and specific surface area (c) of the MOF-derived boron and nitrogen co-doped porous carbon-supported iridium prepared in Example 1 of this invention. Figure 2 These are scanning electron microscope (SEM) images (a), transmission electron microscope (TEM) images (b), and elemental distribution diagrams (c) of the MOF-derived boron and nitrogen co-doped porous carbon-supported iridium prepared in Example 1 of this invention. Figure 3 The linear scan curve (a) and the corresponding Tafel curve (b) of the MOF-derived boron and nitrogen co-doped porous carbon-supported iridium prepared in Example 1 of this invention are shown. Figure 4 The X-ray diffraction pattern (a) and X-ray photoelectron spectrum (b) of the MOF-derived nitrogen-doped porous carbon-supported iridium prepared in Example 2 of this invention are shown. Figure 5This is a scanning electron microscope image of the MOF-derived nitrogen-doped porous carbon-supported iridium prepared in Example 2 of this invention; Figure 6 The linear scan curve (a) and the corresponding Tafel curve (b) of the MOF-derived nitrogen-doped porous carbon-supported iridium prepared in Example 2 of this invention are shown. Figure 7 The X-ray diffraction pattern (a) and X-ray photoelectron spectrum (b) of the MOF-derived boron-doped porous carbon-supported iridium prepared in Example 3 of this invention are shown. Figure 8 This is a scanning electron microscope image of the MOF-derived boron-doped porous carbon-supported iridium prepared in Example 3 of this invention; Figure 9 The linear scan curve (a) and the corresponding Tafel curve (b) of the MOF-derived boron-doped porous carbon-loaded iridium prepared in Example 3 of this invention are shown.

[0018] Figure 10 These are the double-layer capacitors of Embodiments 1, 2, and 3 of the present invention. Detailed Implementation Example 1

[0019] Step 1: Weigh 330 mg of zinc acetate dihydrate and 985 mg of 2-methylimidazole and dissolve them separately in 90 ml of anhydrous ethanol. Then, mix the two solutions, let them stand for 12 h, centrifuge at 8000 rpm for 10 minutes, wash twice with ethanol, and dry in an oven at 60 ℃ to obtain ZIF-8 nanoparticles.

[0020] Step 2: ZIF-8 nanoparticles were placed in a tube furnace and heated at 950 °C for 2 h under a nitrogen atmosphere at a heating rate of 5 °C / min to obtain porous carbon. 15 mg of porous carbon, 5 mg of iridium trichloride, 20 mg of boric acid, and 20 mg of melamine were dispersed in 40 ml of deionized water and stirred in an oil bath at 80 °C for 10 h, then dried at 60 °C for 12 h to obtain a MOF-derived boron-nitrogen co-doped porous carbon-supported iridium precursor. This MOF-derived boron-nitrogen co-doped porous carbon-supported iridium precursor was placed in a tube furnace and heated at 600 °C for 2 h under a nitrogen atmosphere at a heating rate of 5 °C / min to obtain a MOF-derived boron-nitrogen co-doped porous carbon-supported iridium precursor.

[0021] See Figure 1The figures show the X-ray diffraction pattern (a), X-ray photoelectron spectrum (b), and specific surface area (c) of the MOF-derived boron and nitrogen co-doped porous carbon-supported iridium. Figure (a) shows that the sample exhibits (100) and (002) diffraction peaks for C at 2θ = 26° and 42°, respectively, while no peaks for iridium species are observed, indicating that iridium may exist in the form of nanoclusters and at a very low content. Figure (b) shows that the sample contains O, N, C, B, and Ir elements, with binding energies of 530 eV, 398 eV, 284 eV, 298 eV, and 64 eV, respectively, indicating the successful introduction of nitrogen and boron into the carbon substrate. Figure (c) visually shows that the catalyst has a specific surface area of ​​946 m². 2 The / g indicates that the material has a very large specific surface area, which is beneficial for the contact between gas and liquid and catalyst and the direct exchange of substances at the gas-liquid interface in heterogeneous catalysis, thereby accelerating the reaction kinetics.

[0022] See Figure 2 Figure 1 shows the scanning electron microscope (SEM) image (a), transmission electron microscope (TEM) image (b), and elemental distribution map (c) of MOF-derived boron and nitrogen co-doped porous carbon-loaded iridium. Figure 1 shows that the sample size is approximately 400 nm, exhibiting a uniform rhombic octahedron shape. No obvious metal particles were observed on the surface, only some fine carbon particles, possibly due to zinc overflow during heat treatment, which caused carbon to be trapped on the framework surface. Figure 2 shows that the average diameter of the iridium species is only 1.68 nm. TEM further confirmed that the iridium species mostly exist in a metallic state, with measured lattice spacings of 1.9 Å and 2.2 Å, corresponding to the (200) and (111) crystal planes of face-centered cubic iridium, respectively. Figure 2 shows that the elemental distribution map reveals the successful doping of N and B within the carbon framework and further confirms the uniform distribution of Ir clusters on the carbon framework.

[0023] See Figure 3 Figure 1 shows the linear scan curve (a) and corresponding Tafel curve (b) of MOF-derived boron-nitrogen co-doped porous carbon-loaded iridium. As shown in Figure (a), the sample exhibits a hydrazine cracking rate of 10 mA / cm². 2 and 100 mA / cm 2 The overpotentials at these times were 20 mV and 166 mV, respectively, which were superior to the 127 mV and 330 mV of commercial platinum-carbon. As shown in Figure (b), the Tafel slope of the sample was only 11.5 mV / dec, indicating that the sample had excellent reaction kinetics when catalyzing the overall hydrazine cracking. Example 2

[0024] Step 1: Weigh 330 mg of zinc acetate dihydrate and 985 mg of 2-methylimidazole and dissolve them separately in 90 ml of anhydrous ethanol. Then, mix the two solutions, let them stand for 12 h, centrifuge at 8000 rpm for 10 minutes, wash twice with ethanol, and dry in an oven at 60 ℃ to obtain ZIF-8 nanoparticles.

[0025] Step 2: ZIF-8 nanoparticles were placed in a tube furnace and heated at 950 °C for 2 h under a nitrogen atmosphere at a heating rate of 5 °C / min to obtain porous carbon. 15 mg of porous carbon, 5 mg of iridium trichloride, and 20 mg of melamine were dispersed in 40 ml of deionized water and stirred in an oil bath at 80 °C for 10 h, then dried at 60 °C for 12 h to obtain a MOF-derived nitrogen-doped porous carbon-supported iridium precursor. This MOF-derived nitrogen-doped porous carbon-supported iridium precursor was placed in a tube furnace and heated at 600 °C for 2 h under a nitrogen atmosphere to obtain a MOF-derived nitrogen-doped porous carbon-supported iridium precursor.

[0026] See Figure 7 Figure 1 shows the X-ray diffraction pattern (a) and X-ray photoelectron spectrum (b) of the MOF-derived boron-doped porous carbon loaded with iridium. Figure 1 shows that the sample exhibits (100) and (002) diffraction peaks for C at 2θ = 26° and 42°, respectively, while no peaks for iridium species are observed, indicating that iridium may exist in the form of nanoclusters and at a very low concentration. Figure 2 shows that the sample contains O, N, C, and Ir elements, with binding energies of 530 eV, 398 eV, 284 eV, and 64 eV, respectively, indicating successful nitrogen doping of the carbon substrate.

[0027] See Figure 8 The figure shows a scanning electron microscope (SEM) image of the prepared MOF-derived nitrogen-doped porous carbon-supported iridium. As can be seen from the figure, after calcination with only melamine as the nitrogen source, the size of the 18-sided polyhedron is approximately 320 nm, and no obvious metal particles were observed on the surface.

[0028] See Figure 9 Figure 1 shows the linear sweep curve (a) and corresponding Tafel curve (b) of MOF-derived nitrogen-doped porous carbon-supported iridium. As shown in Figure (a), the sample exhibits a high hydrazine splitting velocity at 10 mA / cm². 2 and 100 mA / cm 2 The overpotentials at these times were 36 mV and 183 mV, respectively, which were superior to the 127 mV and 330 mV of commercial platinum-carbon. As shown in Figure (b), the Tafel slope of the sample was only 28.1 mV / dec, indicating that the sample had excellent reaction kinetics when catalyzing the overall hydrazine cracking. Example 3

[0029] Step 1: Weigh 330 mg of zinc acetate dihydrate and 985 mg of 2-methylimidazole and dissolve them separately in 90 ml of anhydrous ethanol. Then, mix the two solutions, let them stand for 12 h, centrifuge at 8000 rpm for 10 minutes, wash twice with ethanol, and dry in an oven at 60 ℃ to obtain ZIF-8 nanoparticles.

[0030] Step 2: ZIF-8 nanoparticles were placed in a tube furnace and heated at 950 °C for 2 h under a nitrogen atmosphere at a heating rate of 5 °C / min to obtain porous carbon. 15 mg of porous carbon, 5 mg of iridium trichloride, and 20 mg of boric acid were dispersed in 40 ml of deionized water and stirred in an oil bath at 80 °C for 10 h, then dried at 60 °C for 12 h to obtain a MOF-derived boron-doped porous carbon-supported iridium precursor. This MOF-derived boron-doped porous carbon-supported iridium precursor was placed in a tube furnace and heated at 600 °C for 2 h under a nitrogen atmosphere at a heating rate of 5 °C / min to obtain a MOF-derived boron-doped porous carbon-supported iridium precursor.

[0031] See Figure 7 Figure 1 shows the X-ray diffraction pattern (a) and X-ray photoelectron spectrum (b) of the MOF-derived nitrogen-doped porous carbon loaded with iridium. Figure 1 shows that the sample exhibits (100) and (002) diffraction peaks for C at 2θ = 26° and 42°, respectively. No peaks for iridium species were observed, indicating that iridium may exist in the form of nanoclusters and at a very low concentration. Figure 2 shows that the sample contains O, N, C, B, and Ir elements, with binding energies of 530 eV, 398 eV, 284 eV, 298 eV, and 64 eV, respectively. Although no additional nitrogen source was added, the N peak at 398 eV is because the original N in ZIF-8 remains after treatment. The presence of B indicates successful boron doping of the carbon substrate.

[0032] See Figure 8 The figure shows a scanning electron microscope (SEM) image of the prepared MOF-derived nitrogen-doped porous carbon-supported iridium. As can be seen from the image, the addition of a boron source and calcination significantly affected the originally well-ordered carbon framework, resulting in spalling and fragmentation. The approximate size is around 400 nm. No obvious metal particles were observed on the surface.

[0033] See Figure 9 Figure 1 shows the linear sweep curve (a) and corresponding Tafel curve (b) of MOF-derived boron-doped porous carbon-loaded iridium. As shown in Figure (a), the sample exhibits a high hydrazine splitting velocity at 10 mA / cm². 2 and 100 mA / cm 2The overpotentials at these times were 27 mV and 322 mV, respectively, which were superior to the 127 mV and 330 mV of commercial platinum-carbon. As shown in Figure (b), the Tafel slope of the sample was only 33.1 mV / dec, indicating that the sample had excellent reaction kinetics when catalyzing the overall hydrazine cracking.

[0034] See Figure 10 Since the electrochemical double-layer capacitance (Cdl) of a catalyst is proportional to the number of its electrochemical active sites, the double-layer capacitances of the three examples are shown in the figure. The Cdl value of Example 1 is 38.33 mF cm⁻¹. -2 This is significantly higher than that of Example 2 (35.96 mF cm⁻¹). -2 Example 3 (21.81 mF cm) -2 The results are consistent with those of LSV, indicating that the prepared MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst has abundant active sites.

[0035] Table 1. Atomic percentages of each element in the prepared catalyst, determined by ICP and XPS. Example 1 3.93 4.77 18.68 72.63 Example 2 2.63 0 15.4 81.97 Example 3 3.64 5.12 12.66 78.58 As shown in Table 1, the introduction of element B not only improved the electrocatalytic hydrazine oxidation performance of the catalyst, but also increased the content of element Ir due to the binding effect of element B with low electronegativity on iridium during pyrolysis. Furthermore, the diameter of Ir nanoclusters was observed to be only 1.68 nm in TEM.

Claims

1. A method for preparing a MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst for monolithic hydrazine decomposition, characterized in that: The steps include the following: Step 1: Weigh 100-500 mg of zinc acetate dihydrate and 985 mg of 2-methylimidazole and dissolve them in 50-90 ml of anhydrous ethanol respectively. After mixing, sonicate for 10-30 min and let stand for 10-24 h to obtain ZIF-8 dispersion. Step 2: Centrifuge, wash and dry the ZIF-8 dispersion obtained in Step 1 to obtain ZIF-8 nanoparticles; Step 3: The ZIF-8 nanoparticles obtained in Step 2 are subjected to carbonization treatment. Under a protective atmosphere, the temperature is increased at a rate of 5℃ / min and held at 950℃ for 2h to obtain nitrogen-doped porous carbon. Step 4: Take 10-20 mg of the nitrogen-doped porous carbon obtained in Step 3, then weigh 5 mg of iridium trichloride, 5-20 mg of boron source, and 5-20 mg of nitrogen source and disperse them in 20-40 ml of water. Stir at 80℃ for 10 h until the reaction is complete, and obtain the precursor solution. Step 5: Centrifuge, wash and dry the precursor solution obtained in Step 4 to obtain precursor particles; Step 6: Place the precursor particles obtained in Step 5 in a tube furnace, and under a protective atmosphere, heat at a rate of 5℃ / min and maintain at 600℃ for 2-4 h to obtain a MOF-derived boron and nitrogen co-doped porous carbon-supported iridium catalyst for overall hydrazine decomposition. Boron and nitrogen doping modulate the electronic structure of iridium, forming composite active sites; Its complex coordination environment corresponds to the local coordination structure formed under the conditions of B and N co-doping.

2. The method for preparing a MOF-derived boron and nitrogen co-doped porous carbon-supported iridium catalyst for monolithic hydrazine decomposition according to claim 1, characterized in that: The solvent used for cleaning in steps 2 and 5 is any one of deionized water, anhydrous ethanol, anhydrous methanol, and isopropanol.

3. The method for preparing a MOF-derived boron and nitrogen co-doped porous carbon-supported iridium catalyst for monolithic hydrazine decomposition according to claim 1, characterized in that: In steps 2 and 5, the drying temperature is 40-65 ℃ and the drying time is 12-24 h.

4. The method for preparing a MOF-derived boron and nitrogen co-doped porous carbon-supported iridium catalyst for monolithic hydrazine decomposition according to claim 1, characterized in that: In steps 2 and 5, the centrifugation speed is 6000-8000 rpm and the time is 5-15 min.

5. The method for preparing a MOF-derived boron and nitrogen co-doped porous carbon-supported iridium catalyst for monolithic hydrazine decomposition according to claim 1, characterized in that: In step 4, the nitrogen source is one or more of the following: urea, melamine, ammonia, cyanamide, and dicyandiamide.

6. The method for preparing a MOF-derived boron and nitrogen co-doped porous carbon-supported iridium catalyst for monolithic hydrazine decomposition according to claim 1, characterized in that: In step 4, the boron source is one or more of boric acid, boron trioxide, and sodium borohydride.

7. A MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst for the integral hydrazine decomposition as described in claim 1, characterized in that: The catalyst comprises the following elements by mass fraction: Ir: 2.63-3.93 wt%, B: 3.21-5.12 wt%, N: 12.66-18.68 wt%, C: 72.63-82.97 wt%, and the MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst has a BET surface area of ​​900-1100 m². 2 / g.

8. The MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst for monolithic hydrazine decomposition according to claim 7, characterized in that: The size of the MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst used for the overall hydrazine decomposition is 320-400 nm.

9. The MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst for monolithic hydrazine decomposition according to claim 7, characterized in that: The active site in the MOF-derived boron-nitrogen co-doped porous carbon-supported iridium catalyst for the overall hydrazine decomposition is Ir-N3B1.

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