Supported iridium oxide catalysts, methods of making the same, proton exchange membrane water electrolysis anodes, and proton exchange membrane water electrolysis cells

Abstract

The present disclosure provides a supported iridium oxide catalyst and a preparation method thereof, a proton exchange membrane water electrolysis anode and a proton exchange membrane water electrolysis cell, the catalyst comprising a composite carrier and a noble metal component; the composite carrier comprises Ce-doped Ti6O 11 ; the noble metal component comprises iridium oxide. The catalyst provided by the present disclosure has more excellent catalytic performance in the PEMWE process.

Description

Technical Field

[0001] This disclosure relates to the preparation technology of electrochemical catalysts, specifically to a supported iridium oxide catalyst and its preparation method, a proton exchange membrane water electrolysis anode, and a proton exchange membrane water electrolyzer. Background Technology

[0002] Proton exchange membrane hydroelectric (PEMWE) technology has the following advantages: First, it produces hydrogen with higher purity, even high-pressure pure hydrogen; second, its excellent proton conductivity results in high efficiency; and third, PEMWE has a small footprint and can be well matched with intermittent power supply. These advantages give PEMWE extremely broad development prospects and it is expected to replace the currently mature alkaline water electrolysis technology in the future. However, PEMWE technology faces the following technical challenges: First, the oxygen evolution reaction at the anode in PEMWE electrolysis of pure water is a four-electron transfer reaction, which is slower kinetics than the hydrogen evolution reaction at the cathode (two-electron transfer), thus limiting the overall efficiency of PEMWE. Therefore, improving the kinetics of the anode oxygen evolution reaction is key to improving the overall efficiency of PEMWE. Second, the high noble metal loading of PEMWE catalysts leads to high costs; and third, PEMWE operates in acidic, high-voltage environments, requiring improvements in catalyst stability and corrosion resistance.

[0003] If iridium dioxide is introduced into the catalyst for PEM electrolysis, the annual production of iridium is low, making it unsuitable for large-scale application in PEM electrolysis. If low-precious metals are introduced into the PEM electrolysis catalyst, the following shortcomings exist: the overall activity of the catalyst still needs to be improved; the precious metal content of the catalyst is difficult to reduce; the catalyst is not evenly dispersed on the support, resulting in severe local agglomeration; the catalyst and the support are only physically bonded, resulting in poor anchoring effect of the support on precious metals and poor long-term stability of the catalyst; and there are also problems with industrial preparation. Summary of the Invention

[0004] The purpose of this disclosure is to provide a supported iridium oxide catalyst and its preparation method, a proton exchange membrane water electrolysis anode, and a proton exchange membrane water electrolyzer to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, a first aspect of this disclosure provides a supported iridium oxide catalyst, comprising a composite support and a noble metal component; said composite support comprising Ce-doped Ti6O 11 The noble metal component includes iridium oxide.

[0006] Optionally, the particle size of the catalyst is 10-500 nm, preferably 20-100 nm; Preferably, the iridium oxide in the catalyst has the chemical formula IrO. xWhere x is any value in the range of 1-3; preferably, IrO x amorphous IrO x .

[0007] Optionally, based on the total weight of the catalyst, the content of the composite support is 80-95% by weight, and the content of the precious metal component is 5-20% by weight; preferably, the content of the composite support is 90-92% by weight, and the content of the precious metal component is 8-10% by weight.

[0008] Optionally, based on the total weight of the catalyst, the Ti6O 11 The content of Ti6O is 50-90% by weight, and the content of Ce element is 2-50% by weight; preferably, the Ti6O 11 The content of Mg is 85-90% by weight, and the content of Ce is 2-10% by weight, wherein the content of Ce is in the form of elemental metal.

[0009] A second aspect of this disclosure provides a method for preparing a supported iridium oxide catalyst, comprising the following steps: S1. The titanium source, cerium source, polyethylene glycol and solvent are subjected to a first mixing treatment and a first heating treatment to obtain a raw material sol; the raw material sol is subjected to a first drying treatment to obtain a carrier precursor; S2. Under a reducing atmosphere, the carrier precursor is subjected to a first sintering treatment to obtain a composite carrier; S3. The composite support, iridium source, alkali and ethylene glycol are subjected to a second mixing treatment and a second heating treatment to obtain a catalyst precursor; S4. The catalyst precursor is subjected to a second sintering treatment under an oxygen-containing atmosphere.

[0010] Optionally, in step S1, the weight ratio of titanium source: cerium source: polyethylene glycol: solvent is 1:0.04-0.5:0.5-3:0.4-10, preferably 1:0.05-0.15:0.5-1.5:0.4-7; Preferably, in the mixed solution obtained from the first mixing treatment, the concentration of the titanium source is 140-160 g / L, the concentration of the polyethylene glycol is 80-280 g / L, and the concentration of the cerium source is 1-25 g / L. Preferably, the concentration of the titanium source is 140-155 g / L, the concentration of the polyethylene glycol is 80-160 g / L, and the concentration of the cerium source is 2-15 g / L.

[0011] Optionally, in step S1, the titanium source is selected from water-soluble salts of titanium; preferably, the titanium source includes titanium oxysulfide. The cerium source is selected from water-soluble salts of cerium sources; preferably, the cerium source includes cerium sulfate. The solvent includes water.

[0012] Optionally, in step S1, the conditions for the first heat treatment include: a heating temperature of 45-70°C and a heating time of 1-30 hours; preferably, a heating temperature of 45-65°C and a heating time of 2-24 hours. The conditions for the first drying process include: a drying temperature of 120-200℃ and a drying time of 24-96h; preferably, the drying temperature is 120-160℃ and the drying time is 36-72h.

[0013] Optionally, in step S2, the conditions for the first sintering treatment include: a sintering temperature of 870-1300℃ and a sintering time of 0.5-8h; preferably, the sintering temperature is 950-1200℃ and the sintering time is 0.5-3h. The reducing atmosphere includes hydrogen and an inert gas. Based on the total volume of the reducing atmosphere, the hydrogen content is 3-10% by volume, preferably 3-5% by volume; optionally, the inert gas includes argon. Preferably, the particle size of the composite carrier obtained in step S2 is 10-500 nm, and more preferably 20-100 nm.

[0014] Optionally, in step S3, the method further includes: mixing the alkali and ethylene glycol, and then mixing them with the composite support and the iridium source; Preferably, in the mixture of alkali and ethylene glycol, the concentration of the alkali is 0.05-0.8 mol / L, more preferably 0.1-0.3 mol / L; Preferably, the amount of the composite carrier is 5-10 mg, more preferably 6-7 mg, based on the volume of 1 mL of the mixed solution of the alkali and ethylene glycol; the amount of the iridium source is 0.5-8 mg, more preferably 1.5-2.5 mg.

[0015] Optionally, in step S3, the iridium source is selected from water-soluble salts of iridium; preferably, the iridium source includes iridium chloride hydrate. The alkali includes sodium hydroxide; Optionally, the method further includes: adding an acid solution to the product after the second heat treatment for pH adjustment, and then performing a second drying treatment on the solid product to obtain a catalyst precursor; optionally, the acid solution is selected from nitric acid solution; optionally, the concentration of the acid solution is 1-5 mol / L, preferably 1-2 mol / L; Optionally, the second drying process is selected from freeze drying or vacuum drying; the freeze drying conditions include: a temperature of -90 to -75°C and a drying time of 24-96 hours; the vacuum drying conditions include: a temperature of 45-75°C and a drying time of 24-96 hours.

[0016] Optionally, in step S3, the conditions for the second heat treatment include: a heating temperature of 160-200℃ and a heating time of 2-12h; preferably, a heating temperature of 170-190℃ and a heating time of 3-5h. Preferably, in step S4, the conditions for the second sintering treatment include: a sintering temperature of 290-450℃ and a sintering time of 1-10h; preferably, a sintering temperature of 300-400℃ and a sintering time of 2-6h; the oxygen-containing atmosphere includes air.

[0017] The third aspect of this disclosure provides a supported iridium oxide catalyst prepared according to the method described in the second aspect of this disclosure.

[0018] The fourth aspect of this disclosure provides a proton exchange membrane water electrolysis anode, comprising the supported iridium oxide catalyst described in the first or third aspect of this disclosure.

[0019] Optionally, in the anode, the supported iridium oxide catalyst is used in the form of an anolyte coating; preferably, the Ir element loading in the anode is 0.05-0.6 mg / cm³. 2 The preferred concentration is 0.08-0.4 mg / cm³. 2 .

[0020] The fifth aspect of this disclosure provides a proton exchange membrane water electrolyzer, including the proton exchange membrane water electrolyzer anode described in the fourth aspect of this disclosure.

[0021] Through the above technical solution, this disclosure provides a supported iridium oxide catalyst and its preparation method, a proton exchange membrane water electrolysis anode, and a proton exchange membrane water electrolyzer. The catalyst includes a composite catalyst and a noble metal component, and the composite support includes Ti6O. 11 And the presence of Ce doping, compared to other types of titanium oxide, Ti6O 11 It exhibits the effect of being rich in oxygen vacancies; the doped Ce component can regulate the electronic state of noble metals; the noble metal component iridium oxide in the catalyst is uniformly distributed on the surface of the composite support, which is beneficial to improving the catalytic performance of the catalyst. Moreover, compared with commercial iridium oxide catalysts, the supported iridium oxide catalyst provided in this disclosure can significantly reduce the loading of noble metal iridium, and can also improve catalytic activity and stability, thereby improving the efficiency of proton exchange membrane water electrolysis process.

[0022] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a TEM image of the catalyst prepared in Example 1 of this disclosure; Figure 2 The XRD pattern of the catalyst prepared in Example 1 of this disclosure; Figure 3 These are test curves of the rotating disk electrode systems of the catalysts obtained in Examples 1-2 and Comparative Examples 1-2 of this disclosure; Figure 4 The graph shows the PEMWE performance test curve of the catalyst prepared in Example 1 of this disclosure. Detailed Implementation

[0024] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure.

[0025] The first aspect of this disclosure provides a supported iridium oxide catalyst, comprising a composite support and a noble metal component; said composite support comprising Ce-doped Ti6O 11 The noble metal component includes iridium oxide.

[0026] This disclosure provides a supported iridium oxide catalyst, which comprises a composite catalyst and a noble metal component, wherein the composite support includes Ti6O. 11 And the presence of Ce doping, compared to other sub-titanium oxide varieties, makes Ti6O... 11 It exhibits an oxygen-vacancy-rich effect; the doped Ce component can modulate the electronic state of the noble metal; the noble metal component iridium oxide in the catalyst is uniformly distributed on the surface of the composite support, which is beneficial to improving the catalytic performance of the catalyst. Moreover, compared with commercial iridium oxide catalysts, the supported iridium oxide catalyst provided in this disclosure can significantly reduce the loading of the noble metal iridium while improving catalytic activity and stability, thereby improving the efficiency of proton exchange membrane water electrolysis process.

[0027] In one embodiment, the catalyst has a particle size of 10-500 nm, preferably 20-100 nm. The catalyst provided in this disclosure has a nanoscale size, which can increase the overall specific surface area of ​​the catalyst, thereby giving the catalyst a better catalytic effect.

[0028] In one specific embodiment, the iridium oxide in the catalyst has the chemical formula IrO. x Where x is any value in the range of 1-3; preferably, IrO x amorphous IrO x .

[0029] In one embodiment, based on the total weight of the catalyst, the content of the composite support is 80-95% by weight, and the content of the noble metal component is 5-20% by weight; preferably, the content of the composite support is 90-92% by weight, and the content of the noble metal component is 8-10% by weight. When the content of the composite support and the noble metal component in the supported iridium oxide catalyst is within the range of this embodiment, and especially within the preferred range, the catalyst can exhibit high catalytic activity and stability while reducing the loading of the noble metal Ir.

[0030] In one embodiment, the total weight of the catalyst is used as a basis, and the Ti6O 11 The content of Ti6O is 50-90% by weight, and the content of Ce element is 2-50% by weight; preferably, the Ti6O 11 The content of [agent] is 85-90% by weight, and the content of Ce element is 2-10% by weight, wherein the content of Ce element is in the form of elemental metal. Having the composition of the composite support in this embodiment, especially having the preferred composition of the composite support, can further improve the catalytic performance of the catalyst.

[0031] A second aspect of this disclosure provides a method for preparing a supported iridium oxide catalyst, comprising the following steps: S1. The titanium source, cerium source, polyethylene glycol and solvent are subjected to a first mixing treatment and a first heating treatment to obtain a raw material sol; the raw material sol is subjected to a first drying treatment to obtain a carrier precursor; S2. Under a reducing atmosphere, the carrier precursor is subjected to a first sintering treatment to obtain a composite carrier; S3. The composite support, iridium source, alkali and ethylene glycol are subjected to a second mixing treatment and a second heating treatment to obtain a catalyst precursor; S4. The catalyst precursor is subjected to a second sintering treatment under an oxygen-containing atmosphere.

[0032] This disclosure provides a method for preparing a supported iridium oxide catalyst. First, a titanium source, a cerium source, polyethylene glycol, and a solvent are mixed and heated to obtain a raw material sol, in which the titanium and cerium sources are uniformly dispersed. The raw material sol is dried to obtain a support precursor, which is then subjected to a first sintering treatment under a reducing atmosphere to obtain a composite support. The composite support is then mixed with an iridium source, an alkaline solution, and ethylene glycol and heated to achieve uniform dispersion of the iridium source on the surface of the composite support. Finally, the catalyst precursor is subjected to a second sintering treatment in an oxygen-containing atmosphere to form a uniformly distributed IrO layer on the surface of the composite support. x The preparation method disclosed herein is beneficial for large-scale industrial production.

[0033] In a preferred embodiment, in step S1, the weight ratio of titanium source: cerium source: polyethylene glycol: solvent is 1:0.04-0.5:0.5-3:0.4-10, preferably 1:0.05-0.15:0.5-1.5:0.4-7. The composite support prepared according to the raw material ratio in this embodiment, especially the composite support prepared according to the preferred raw material ratio, can obtain a catalyst with better performance.

[0034] In one specific embodiment, in the mixed solution obtained by the first mixing treatment, the concentration of the titanium source is 140-160 g / L, the concentration of the polyethylene glycol is 80-280 g / L, and the concentration of the cerium source is 1-25 g / L. Preferably, the concentration of the titanium source is 140-155 g / L, the concentration of the polyethylene glycol is 80-160 g / L, and the concentration of the cerium source is 2-15 g / L. Preparing the composite carrier according to the raw material concentrations in this embodiment, especially according to the preferred raw material concentrations, can yield a composite carrier with superior performance.

[0035] In one specific embodiment, in step S1, the titanium source is selected from water-soluble salts of titanium; preferably, the titanium source includes titanium oxysulfide. The cerium source is selected from water-soluble salts of cerium sources; preferably, the cerium source includes cerium sulfate. The solvent includes water. All raw materials used in this embodiment can be purchased through ordinary commercial channels or prepared using known methods.

[0036] In one implementation method, in step S1, the conditions for the first heat treatment include: a heating temperature of 45-70°C and a heating time of 1-30 hours; preferably, the heating temperature is 45-65°C and the heating time is 2-24 hours. The conditions for the first drying treatment include: a drying temperature of 120-200℃ and a drying time of 24-96 h; preferably, a drying temperature of 120-160℃ and a drying time of 36-72 h. By preparing the support precursor according to the process conditions in this embodiment, particularly the preferred process conditions, the uniformity of the noble metal source doping in the support precursor is improved, thereby enhancing the catalytic effect of the final catalyst product in the proton exchange membrane water electrolysis process.

[0037] In one embodiment, in step S2, the conditions for the first sintering treatment include: a sintering temperature of 870-1300℃ and a sintering time of 0.5-8h, preferably, a sintering temperature of 950-1200℃ and a sintering time of 0.5-3h; The reducing atmosphere includes hydrogen and an inert gas. Based on the total volume of the reducing atmosphere, the hydrogen content is 3-10% by volume, preferably 3-5% by volume. Optionally, the inert gas includes argon. According to the process conditions of the first sintering treatment in this embodiment, especially according to the preferred conditions, the reduction effect of the composite support can be improved. For example, by increasing the sintering temperature, the particle size of the composite support can be increased. By controlling the time of the first sintering treatment, the particle size of the resulting composite support and the final catalyst product can be controlled within a suitable range.

[0038] In one specific embodiment, the particle size of the composite carrier obtained in step S2 is 10-500 nm, preferably 20-100 nm.

[0039] In one embodiment, step S3 further includes: mixing the alkali and ethylene glycol, and then mixing them with the composite carrier and the iridium source; Preferably, in the mixture of alkali and ethylene glycol, the concentration of the alkali is 0.05-0.8 mol / L, more preferably 0.1-0.3 mol / L; Preferably, based on the volume of 1 mL of the mixed solution of the alkali and ethylene glycol, the amount of the composite support is 5-10 mg, more preferably 6-7 mg; the amount of the iridium source is 0.5-8 mg, more preferably 1.5-2.5 mg. Mixing according to the raw material ratios in this embodiment, especially according to the preferred raw material ratios, can prepare a catalyst with superior performance.

[0040] In one specific embodiment, in step S3, the iridium source is selected from water-soluble salts of iridium; preferably, the iridium source includes iridium chloride hydrate. The base includes sodium hydroxide. All reagents used in this disclosure are readily available through commercial channels or prepared using known methods.

[0041] In one specific embodiment, the method further includes: adding an acid solution to the product after the second heat treatment for pH adjustment, and then performing a second drying treatment on the solid product to obtain a catalyst precursor; optionally, the acid solution is selected from nitric acid solution; optionally, the concentration of the acid solution is 1-5 mol / L, preferably 1-2 mol / L; Optionally, the second drying process is selected from freeze drying or vacuum drying; the freeze drying conditions include: a temperature of -90 to -75°C and a drying time of 24-96 hours; the vacuum drying conditions include: a temperature of 45-75°C and a drying time of 24-96 hours.

[0042] In one embodiment, in step S3, the conditions for the second heat treatment include: a heating temperature of 160-200℃ and a heating time of 2-12h; preferably, a heating temperature of 170-190℃ and a heating time of 3-5h, which is beneficial for uniform mixing and can improve the uniformity of the distribution of noble metal components on the composite carrier.

[0043] In one embodiment, in step S4, the conditions for the second sintering treatment include: a sintering temperature of 290-450°C and a sintering time of 1-10 hours; preferably, a sintering temperature of 300-400°C and a sintering time of 2-6 hours; the oxygen-containing atmosphere includes air. By performing the second sintering treatment according to the conditions of this embodiment, particularly according to the preferred process conditions, a catalyst with better catalytic performance can be prepared.

[0044] The third aspect of this disclosure provides a supported iridium oxide catalyst prepared according to the method described in the second aspect of this disclosure.

[0045] The fourth aspect of this disclosure provides a proton exchange membrane water electrolysis anode, comprising the supported iridium oxide catalyst described in the first or third aspect of this disclosure.

[0046] In a preferred embodiment, the supported iridium oxide catalyst is used in the anode as an anolyte coating. Preferably, the Ir element loading in the anode is 0.05-0.6 mg / cm³. 2 The preferred concentration is 0.08-0.4 mg / cm³. 2 The anodic coating with the Ir element loading of this embodiment can improve the efficiency of the proton exchange membrane water electrolysis process.

[0047] In one specific embodiment, the supported iridium oxide catalyst can be used as a coating in the proton exchange membrane water electrolysis anode.

[0048] The fifth aspect of this disclosure provides a proton exchange membrane water electrolyzer, including the proton exchange membrane water electrolyzer anode described in the fourth aspect of this disclosure.

[0049] In one specific embodiment, the proton exchange membrane water electrolyzer includes a proton exchange membrane, a cathode catalyst layer, an anode catalyst layer, a cathode diffusion layer, and an anode diffusion layer; the anode catalyst layer includes the supported iridium oxide catalyst.

[0050] In one specific embodiment, the conditions for proton exchange membrane electrolysis (PEMWE) hydrogen production using the aforementioned proton exchange membrane electrolyzer include: a voltage of 1-2V and a current density of 1-4mA / cm². 2The temperature is 60-80℃, and the time is 1-2000h. Using the process conditions described in this embodiment is beneficial for improving the process effect of PEMWE.

[0051] In one specific embodiment, the conditions for using the proton exchange membrane water electrolysis (PEMWE) hydrogen production process in the aforementioned proton exchange membrane water electrolyzer include: a voltage of 1.85V and a current density of 2mA / cm². 2 The temperature was 80℃, and the time was 1500h. In this disclosure, the structure and material of the proton exchange membrane water electrolyzer can be selected from those in the field.

[0052] The present disclosure is described in detail below with reference to embodiments, but this does not limit the scope of the disclosure.

[0053] All raw materials used in the embodiments of this disclosure can be obtained through commercial purchase.

[0054] In the following examples and comparative examples, the TEM images of the samples were obtained using a TEM, Talos F200X G2, 200 kV instrument; The XRD patterns of the samples were obtained using an XRD, Mini Flex 600 instrument. The test conditions included: Cu Kα (λ = 1.5406 Å), a scan range of 5°–90°, and a scan rate of 5° min. -1 ; The particle size of the sample was measured using a TEM, Talos F200X G2, 200 kV instrument. The component content of the samples was determined using ICP-MS with a NexION 2000 instrument.

[0055] Example 1 (1) Synthesis of the carrier precursor: Titanium oxysulfide (titanium source), polyethylene glycol, and cerium sulfate (cerium source) were dissolved in pure water (solvent) to form a mixed solution. The concentration of titanium oxysulfide in the mixed solution was 150 g / L, the concentration of cerium sulfate was 15 g / L, and the concentration of polyethylene glycol was 150 g / L. The weight ratio of titanium source:cerium source:polyethylene glycol:solvent was 1:0.1:1:6.67. The mixed solution was stirred at room temperature for 5 min (first mixing treatment). The mixed system was then heated in an oil bath at 45 °C for 24 h (first heating treatment) to form a raw material sol. The raw material sol was dried at 150 °C under normal pressure for 48 h (first drying treatment) to obtain the carrier precursor.

[0056] (2) First sintering treatment of the carrier precursor: The carrier precursor obtained in step (1) was placed in a tube furnace and subjected to a first sintering treatment in a hydrogen-argon mixed atmosphere (reducing atmosphere), wherein the hydrogen concentration in the hydrogen-argon mixed atmosphere was 3% by volume, the sintering temperature was 1000℃, and the sintering time was 1h, to obtain the composite carrier. The sintered composite carrier Ce-Ti6O 11 The particle size is 20-50 nm.

[0057] (3) Noble metal loading: Sodium hydroxide was dissolved in ethylene glycol to prepare a 0.3 mol / L sodium hydroxide solution. 12 mg of iridium chloride hydrate (IrCl3-nH2O, iridium source) was completely dissolved in 5 mL of the above solution, and then 35 mg of Ce-Ti6O was added. 11 The substrate (composite support) was uniformly dispersed (second mixing treatment). The amount of composite support was 7 mg and the amount of iridium source was 2.4 mg, based on a volume of 1 mL of the mixture of the base and ethylene glycol. The resulting homogeneous mixture was heated at 170 °C for 5 h (second heating treatment), and then cooled to room temperature to obtain the reaction mixture. 20 mL of 2 mol / L nitric acid solution was added to the reaction mixture for pH adjustment. After centrifugation, the precipitate was washed and then dried (second drying treatment) at 60 °C for 48 h to obtain the catalyst precursor.

[0058] (4) Second sintering treatment of catalyst precursor: The catalyst precursor powder was sintered in air at 360°C for 3 h to obtain Ce-doped Ti6O 11 Load IrO x Catalyst.

[0059] The TEM image of the catalyst prepared in this embodiment is as follows: Figure 1 As shown, by Figure 1 It can be seen that the noble metal components (iridium oxide, amorphous IrO) in this catalyst x (where x is any value in the range of 1-3) are distributed on the surface of the composite support, and the catalyst particle size is approximately 30 nm.

[0060] The XRD pattern of the catalyst prepared in this embodiment is as follows: Figure 2 As shown, by Figure 2 It can be seen that, compared with standard Ti6O 11 Compared to the spectra, the composite support for the catalyst prepared in this embodiment includes Ti6O. 11 The carrier of form.

[0061] Example 2 (1) Synthesis of the carrier precursor: Titanium oxysulfide (titanium source), polyethylene glycol, and cerium sulfate (cerium source) were dissolved in pure water (solvent) to form a mixed solution; the concentration of titanium oxysulfide in the mixed solution was 150 g / L, the concentration of cerium sulfate was 6 g / L, and the concentration of polyethylene glycol was 100 g / L, wherein the weight ratio of titanium source:cerium source:polyethylene glycol:solvent was 1:0.04:0.67:6.67. After stirring the mixed solution at room temperature for 30 min (first mixing treatment), the mixed system was heated in an oil bath at 50 °C for 20 h (first heating treatment) to form a raw material sol. The raw material sol was dried at 130 °C under normal pressure for 48 h (first drying treatment) to obtain the carrier precursor.

[0062] (2) First sintering treatment of the carrier precursor: The carrier precursor obtained in step (1) was placed in a tube furnace and subjected to a first sintering treatment in a hydrogen-argon mixed atmosphere (reducing atmosphere), wherein the hydrogen concentration in the hydrogen-argon mixed atmosphere was 5% by volume, the sintering temperature was 950℃, and the sintering time was 3h, to obtain the composite carrier. The obtained composite carrier Ce-Ti6O 11 The particle size is 50-100nm.

[0063] (3) Noble metal loading: Sodium hydroxide was dissolved in ethylene glycol to prepare a 0.2 mol / L sodium hydroxide solution. 12 mg of iridium chloride hydrate (IrCl3-nH2O, iridium source) was completely dissolved in 4 mL of the above solution, and then 35 mg of Ce-Ti6O was added. 11 The substrate (composite support) was uniformly dispersed (second mixing treatment). The amount of composite support was 8.75 mg and the amount of iridium source was 3 mg, based on a volume of 1 mL of the mixture of the base and ethylene glycol. The resulting homogeneous mixture was heated at 190 °C for 3 h (second heating treatment), and then cooled to room temperature to obtain the reaction mixture. 15 mL of a 2 mol / L nitric acid solution was added to the reaction mixture for pH adjustment. After centrifugation, the precipitate was washed and then dried (second drying treatment) at 70 °C for 36 h to obtain the catalyst precursor.

[0064] (4) Second sintering treatment of catalyst precursor: The catalyst precursor powder was sintered in air at 360°C for 4 h to obtain Ce-doped Ti6O 11 Load IrO x Catalyst.

[0065] Example 3 (1) Synthesis of the carrier precursor: Titanium oxysulfide (titanium source), polyethylene glycol, and cerium sulfate (cerium source) were dissolved in pure water (solvent) to form a mixed solution; the concentration of titanium oxysulfide in the mixed solution was 160 g / L, the concentration of cerium sulfate was 20 g / L, and the concentration of polyethylene glycol was 200 g / L, wherein the weight ratio of titanium source:cerium source:polyethylene glycol:solvent was 1:0.125:1.25:6.25. After stirring the mixed solution at room temperature for 20 min (first mixing treatment), the mixed system was heated in an oil bath at 60℃ for 4 h (first heating treatment) to form a raw material sol. The raw material sol was dried at 160℃ under normal pressure for 24 h to form the carrier precursor.

[0066] (2) First sintering treatment of the carrier precursor: The carrier precursor obtained in step (1) was placed in a tube furnace and subjected to a first sintering treatment in a hydrogen-argon mixed atmosphere (reducing atmosphere), wherein the hydrogen concentration in the hydrogen-argon mixed atmosphere was 7% by volume, the sintering temperature was 950℃, and the sintering time was 2h, to obtain the composite carrier. The sintered composite carrier Ce-Ti6O 11 The particle size is 40-50nm.

[0067] (3) Noble metal loading: Sodium hydroxide was dissolved in ethylene glycol to prepare a 0.1 mol / L sodium hydroxide solution. 12 mg of iridium chloride hydrate (IrCl3-nH2O, iridium source) was completely dissolved in 2 mL of the above solution, and then 35 mg of Ce-Ti6O was added. 11 The substrate (composite support) was uniformly dispersed (second mixing treatment). The amount of composite support was 7 mg and the amount of iridium source was 2.4 mg, based on a volume of 1 mL of the mixture of the base and ethylene glycol. The resulting homogeneous mixture was heated at 55 °C for 10 h (second heating treatment), and then cooled to room temperature to obtain the reaction mixture. 20 mL of 2 mol / L nitric acid solution was added to the reaction mixture for pH adjustment. After centrifugation, the precipitate was washed and then dried using freeze-drying (drying temperature -80 °C) for 48 h to obtain the catalyst precursor.

[0068] (4) Second sintering treatment of catalyst precursor: The catalyst precursor powder was sintered in air at 360°C for 2 h to obtain Ce-doped Ti6O 11 Load IrO x Catalyst.

[0069] Example 4 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in the following aspects: The catalyst prepared in step (1) has the following characteristics: titanium oxysulfide concentration of 160 g / L, cerium sulfate concentration of 25 g / L, and polyethylene glycol concentration of 280 g / L. The weight ratio of titanium source: cerium source: polyethylene glycol: solvent is 1:0.156:1.75:6.25. The rest of the process is the same as in Example 1.

[0070] Example 5 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in the following aspects: In step (3), the amount of composite support used is 5 mg and the amount of iridium source used is 25 mg, based on the volume of 1 mL of the mixed solution of the alkali and ethylene glycol; the rest of the process is the same as in Example 1; the catalyst is prepared.

[0071] Example 6 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: In step (1), the mixed system was heated in an oil bath at 70°C for 1 hour (first heat treatment) to form a raw material sol. The raw material sol was dried at 120°C under normal pressure for 96 hours (first drying treatment) to obtain the support precursor. The remaining process was the same as in Example 1 to prepare the catalyst.

[0072] Example 7 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: The conditions for the first sintering treatment of the support precursor in step (2) were adjusted to: a hydrogen concentration of 7% by volume in the hydrogen-argon mixture, a sintering temperature of 900°C, and a sintering time of 4 hours, to obtain the composite support. The remaining processes were the same as in Example 1, and the catalyst was prepared.

[0073] Example 8 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: The conditions for the second sintering treatment in step (4) were adjusted as follows: the catalyst precursor powder was sintered in air at 290°C for 6 hours, and the rest of the process was the same as in Example 1, and the catalyst was prepared.

[0074] Comparative Example 1 A commercial iridium dioxide catalyst (purchased from Aladdin) was used.

[0075] Comparative Example 2 Commercial IrO2-NbO x The catalyst (purchased from Umicore) had an Ir content of 75% by weight based on the total weight of the catalyst.

[0076] Comparative Example 3 This comparative example follows the preparation method described in Example 1, but differs from Example 1 in that: In step (1), cerium sulfate (cerium source) is not added, and the rest of the process is the same as in Example 1 to prepare the catalyst.

[0077] Comparative Example 4 This comparative example follows the preparation method described in Example 1, but differs from Example 1 in that: The first sintering treatment in step (2) is not performed; the rest of the process is the same as in Example 1, and the catalyst is prepared.

[0078] The content of composite support and noble metal components in the catalysts obtained in the above examples and comparative examples, and the content of Ti6O in the composite support... 11 The data on Ce content, catalyst particle size, etc. are listed in Table 1 below.

[0079] Table 1

[0080] Test Example 1 This test example illustrates the performance of the catalysts obtained in the above embodiments and comparative examples in a rotating disk electrode system. It includes the following steps: The intrinsic electrochemical activity of the material was tested in a typical three-electrode system using a rotating disk electrode as the working electrode, a gold electrode as the counter electrode, a mercury / mercurous sulfate electrode as the reference electrode, and 0.1 M HClO4 as the electrolyte. The tests showed that the current density of the catalyst in the rotating disk electrode system was 10 mA / cm² when using different catalysts. 2 The overpotential at that time (compared to the standard potential of 1.23V) was determined, and the test results are listed in Table 2 below.

[0081] Table 2

[0082] Based on the data in Table 1-2 above, it can be seen that: Comparative Example 1 used a commercial iridium dioxide catalyst, while Comparative Example 2 used a commercial IrO2-NbO catalyst. x In the catalysts of Comparative Examples 1-2, the iridium content was 75% by weight and 100% by weight, while the iridium content in the catalysts provided in this disclosure is significantly lower than that in Comparative Examples 1-2; and the catalysts prepared using Examples 1-8 of this disclosure showed a current density of 10 mA / cm² in the rotating disk electrode system test. 2 The lower overpotential indicates that the catalysts in Examples 1-8 possess superior catalytic performance while having lower noble metal content, exhibiting higher catalytic activity for the oxygen evolution reaction. The current density versus voltage curves of the catalysts obtained in Examples 1-2 and Comparative Examples 1-2 in the rotating disk electrode system test are shown in the figure below. Figure 3As shown in the figure, the catalysts obtained in Examples 1-2 exhibit better performance at a current density of 10 mA / cm². 2 The overpotentials at all times were less than those in Comparative Example 1-2; Comparative Example 3 did not include a cerium source in the preparation process of the composite support, and Comparative Example 4 did not perform the first sintering treatment under a reducing atmosphere during the preparation of the composite support; the remaining processes were the same as in Example 1. Compared with the catalyst of Example 1, the catalyst prepared in Comparative Examples 3-4 showed a current density of 10 mA / cm² in the rotating disk electrode system test. 2 The overpotential is lower, which means the catalytic performance is better and the catalytic activity for the oxygen evolution reaction is higher. Comparing Example 1 and Example 4, it can be seen that in Example 1, the composite support was prepared according to the preferred weight ratio of titanium source: cerium source: polyethylene glycol: solvent provided in this disclosure during the catalyst preparation process. The catalyst obtained in Example 1 had a current density of 10 mA / cm² in the rotating disk electrode system test. 2 The overpotential is lower, which means the catalytic performance is better and the catalytic activity for the oxygen evolution reaction is higher. Comparing Example 1 and Example 5, it can be seen that in the preparation process of Example 1, noble metal loading is achieved by using the preferred amounts of alkali, ethylene glycol, composite support, and iridium source. The catalyst prepared in Example 1 contains a composite support and IrO... x The content is within the preferred range provided in this disclosure, and the catalyst obtained in Example 1 has a current density of 10 mA / cm² in the rotating disk electrode system test. 2 The overpotential is lower, which means the catalytic performance is better and the catalytic activity for the oxygen evolution reaction is higher. Comparing Example 1 with Example 6, it can be seen that Example 1 prepared the composite support by performing the first heat treatment and first drying treatment according to the preferred process conditions; comparing Example 1 with Example 7, it can be seen that Example 1 prepared the composite support under a reducing atmosphere according to the preferred first sintering treatment conditions. Compared with the catalysts prepared in Examples 6-7, the catalyst obtained in Example 1 has a smaller particle size and a current density of 10 mA / cm² in the rotating disk electrode system test. 2 The overpotential is lower, which means the catalytic performance is better and the catalytic activity for the oxygen evolution reaction is higher. Comparing Example 1 and Example 8, it can be seen that Example 1, performed according to the preferred process conditions provided in this disclosure, resulted in a smaller particle size of the catalyst and a current density of 10 mA / cm² in the rotating disk electrode system test. 2 The overpotential is lower, which means the catalytic performance is better and the catalytic activity for the oxygen evolution reaction is higher.

[0083] Test Example 2 This test example illustrates the performance of the catalyst materials prepared in the above examples and comparative examples in the PEMWE system. It includes the following steps: The catalysts obtained in the examples and comparative examples were used as the catalyst layer, with an anode catalyst loading of 0.2 mg / cm³. 2 The anode diffusion layer is a platinum-plated titanium felt with a thickness of 0.25 mm; the cathode Pt / C loading is 0.2 mg / cm³. 2 The cathode diffusion layer was carbon paper with a thickness of 0.3 mm; the proton exchange membrane was purchased from Chemours and had a thickness of 0.127 mm; the test current density was 0-4 A / cm². 2 The test temperature was 80℃, and the test time was 0.5 hours. The electrolysis process achieved an efficiency of 2 A / cm. 2 The voltage at that time was recorded, and the test results are listed in Table 3 below.

[0084] Table 3

[0085] As shown in Table 3, compared with the commercial catalysts in Comparative Examples 1-2, the catalysts prepared using the method provided in this disclosure in Examples 1-8 achieved 2 A / cm² in the PEMWE system test. 2 The lower voltage indicates that the catalysts in Examples 1-8 have higher catalytic activity, thus improving electrolysis efficiency; Comparing Example 1 and Example 4, it can be seen that Example 1, in its catalyst preparation process, prepared a composite support according to the preferred weight ratio of titanium source: cerium source: polyethylene glycol: solvent provided in this disclosure. The catalyst obtained in Example 1 achieved 2 A / cm² in the PEMWE system test. 2 The lower voltage indicates that the catalyst in Example 1 has higher catalytic activity, thus improving electrolysis efficiency; the current-voltage relationship curve of the catalyst obtained in Example 1 in the PEMWE test is shown in the figure below. Figure 4 As shown; Comparing Example 1 and Example 5, it can be seen that in the preparation process of Example 1, noble metal loading was carried out according to the preferred amounts of alkali, ethylene glycol, composite support, and iridium source. The catalyst obtained in Example 1 achieved 2 A / cm in the PEMWE system test. 2 The lower voltage indicates that the catalyst in Example 1 has higher catalytic activity, thus improving electrolysis efficiency; Comparing Example 1 with Example 6, it can be seen that Example 1 prepared the composite support by performing the first heat treatment and first drying treatment according to the preferred process conditions; comparing Example 1 with Example 7, it can be seen that Example 1 prepared the composite support under a reducing atmosphere according to the preferred first sintering treatment conditions. Compared with the catalysts prepared in Examples 6-7, the catalyst obtained in Example 1 achieved 2 A / cm in the PEMWE system test.2 The lower voltage indicates that the catalyst in Example 1 has higher catalytic activity, thus improving electrolysis efficiency; Comparing Example 1 and Example 8, it can be seen that Example 1, performed with the preferred process conditions provided in this disclosure for the second sintering treatment, yielded a catalyst with a PEMWE system performance of 2 A / cm². 2 The lower voltage indicates that the catalyst in Example 1 has higher catalytic activity, thus improving electrolysis efficiency.

[0086] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0087] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0088] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A supported iridium oxide catalyst, characterized in that, It includes a composite support and a noble metal component; the composite support includes Ce-doped Ti6O. 11 The noble metal component includes iridium oxide.

2. The catalyst according to claim 1, characterized in that, The catalyst has a particle size of 10-500 nm, preferably 20-100 nm; Preferably, the iridium oxide in the catalyst has the chemical formula IrO. x Where x is any value in the range of 1-3; preferably, IrO x amorphous IrO x .

3. The catalyst according to claim 1, characterized in that, Based on the total weight of the catalyst, the content of the composite support is 80-95% by weight, and the content of the precious metal component is 5-20% by weight; preferably, the content of the composite support is 90-92% by weight, and the content of the precious metal component is 8-10% by weight.

4. The catalyst according to claim 1, characterized in that, Based on the total weight of the catalyst, the Ti6O 11 The content of Ti6O is 50-90% by weight, and the content of Ce element is 2-50% by weight; preferably, the Ti6O 11 The content of Mg is 85-90% by weight, and the content of Ce is 2-10% by weight, wherein the content of Ce is in the form of elemental metal.

5. A method for preparing a supported iridium oxide catalyst, characterized in that, Includes the following steps: S1. The titanium source, cerium source, polyethylene glycol and solvent are subjected to a first mixing treatment and a first heating treatment to obtain a raw material sol; the raw material sol is subjected to a first drying treatment to obtain a carrier precursor; S2. Under a reducing atmosphere, the carrier precursor is subjected to a first sintering treatment to obtain a composite carrier; S3. The composite support, iridium source, alkali and ethylene glycol are subjected to a second mixing treatment and a second heating treatment to obtain a catalyst precursor. S4. The catalyst precursor is subjected to a second sintering treatment under an oxygen-containing atmosphere.

6. The method according to claim 5, characterized in that, In step S1, the weight ratio of titanium source: cerium source: polyethylene glycol: solvent is 1:0.04-0.5:0.5-3:0.4-10, preferably 1:0.05-0.15:0.5-1.5:0.4-7; Preferably, in the mixed solution obtained from the first mixing treatment, the concentration of the titanium source is 140-160 g / L, the concentration of the polyethylene glycol is 80-280 g / L, and the concentration of the cerium source is 1-25 g / L. Preferably, the concentration of the titanium source is 140-155 g / L, the concentration of the polyethylene glycol is 80-160 g / L, and the concentration of the cerium source is 2-15 g / L.

7. The method according to claim 5, characterized in that, In step S1, the titanium source is selected from water-soluble salts of titanium; preferably, the titanium source includes titanium oxysulfide. The cerium source is selected from water-soluble salts of cerium sources; preferably, the cerium source includes cerium sulfate. The solvent includes water.

8. The method according to claim 5, characterized in that, In step S1, the conditions for the first heat treatment include: a heating temperature of 45-70℃ and a heating time of 1-30h; preferably, a heating temperature of 45-65℃ and a heating time of 2-24h. The conditions for the first drying process include: a drying temperature of 120-200℃ and a drying time of 24-96h; preferably, the drying temperature is 120-160℃ and the drying time is 36-72h.

9. The method according to claim 5, characterized in that, In step S2, the conditions for the first sintering treatment include: a sintering temperature of 870-1300℃ and a sintering time of 0.5-8h, preferably, a sintering temperature of 950-1200℃ and a sintering time of 0.5-3h; The reducing atmosphere includes hydrogen and an inert gas. Based on the total volume of the reducing atmosphere, the hydrogen content is 3-10% by volume, preferably 3-5% by volume; optionally, the inert gas includes argon. Preferably, the particle size of the composite carrier obtained in step S2 is 10-500 nm, and more preferably 20-100 nm.

10. The method according to claim 5, characterized in that, In step S3, the method further includes: mixing the alkali and ethylene glycol, and then mixing them with the composite support and the iridium source; Preferably, in the mixture of alkali and ethylene glycol, the concentration of the alkali is 0.05-0.8 mol / L, more preferably 0.1-0.3 mol / L; Preferably, the amount of the composite carrier is 5-10 mg, more preferably 6-7 mg, based on the volume of 1 mL of the mixed solution of the alkali and ethylene glycol; the amount of the iridium source is 0.5-8 mg, more preferably 1.5-2.5 mg.

11. The method according to claim 5, characterized in that, In step S3, the iridium source is selected from water-soluble salts of iridium; preferably, the iridium source includes iridium chloride hydrate. The alkali includes sodium hydroxide; Optionally, the method further includes: adding an acid solution to the product after the second heat treatment for pH adjustment, and then performing a second drying treatment on the solid product to obtain a catalyst precursor; optionally, the acid solution is selected from nitric acid solution; optionally, the concentration of the acid solution is 1-5 mol / L, preferably 1-2 mol / L; Optionally, the second drying process is selected from freeze drying or vacuum drying; the freeze drying conditions include: a temperature of -90 to -75°C and a drying time of 24-96 hours; the vacuum drying conditions include: a temperature of 45-75°C and a drying time of 24-96 hours.

12. The method according to claim 5, characterized in that, In step S3, the conditions for the second heat treatment include: a heating temperature of 160-200℃ and a heating time of 2-12h; preferably, a heating temperature of 170-190℃ and a heating time of 3-5h. Preferably, in step S4, the conditions for the second sintering treatment include: a sintering temperature of 290-450℃ and a sintering time of 1-10h; preferably, a sintering temperature of 300-400℃ and a sintering time of 2-6h; the oxygen-containing atmosphere includes air.

13. The supported iridium oxide catalyst prepared by the method according to any one of claims 5-12.

14. A proton exchange membrane water electrolysis anode, characterized in that, Includes the supported iridium oxide catalyst according to any one of claims 1-4 and 13.

15. The proton exchange membrane water electrolysis anode according to claim 14, characterized in that, In the anode, the supported iridium oxide catalyst is used in the form of an anode coating; Preferably, the Ir element loading in the anode is 0.05-0.6 mg / cm³. 2 The preferred concentration is 0.08-0.4 mg / cm³. 2 .

16. A proton exchange membrane water electrolyzer, characterized in that, Includes the proton exchange membrane water electrolysis anode as described in claim 14 or 15.

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