阅读说明：本技术 一种非碳基低成本析氧催化剂及其制备方法 (Non-carbon-based low-cost oxygen evolution catalyst and preparation method thereof ) 是由 贺高红 李楠楠 焉晓明 高莉 胡磊 底梦婷 孙小军 刘杰 于 2021-10-26 设计创作，主要内容包括：本发明公开了一种非碳基低成本析氧催化剂及其制备方法,属于阴离子交换膜电解水制氢技术领域。本发明首先合成了具有性能和稳定性优良的Co-(3)O-(4)/TiN催化剂,再在此基础上通过气相沉积选择性磷化法制得CoP@TiO-(2)催化剂。所制备的CoP@TiO-(2)催化剂具有较好性能和稳定性,可应用于阴离子交换膜电解水制氢电池中。(The invention discloses a non-carbon-based low-cost oxygen evolution catalyst and a preparation method thereof, belonging to the technical field of hydrogen production by water electrolysis through an anion exchange membrane. The invention firstly synthesizes Co with excellent performance and stability 3 O 4 TiN catalyst, and then CoP @ TiO is prepared by vapor deposition selective phosphating method on the basis 2 A catalyst. Prepared CoP @ TiO 2 The catalyst has better performance and stability, and can be applied to a cell for producing hydrogen by electrolyzing water through an anion exchange membrane.)

1. A non-carbon based low-cost oxygen evolution catalyst is characterized in that the non-carbon based low-cost oxygen evolution catalyst is CoP @ TiO₂The catalyst has the following structure:

[email protected]₂the catalyst mainly comprises CoP and TiO₂Two components, CoP and TiO₂Forming a heterojunction structure, wherein the appearance of the heterojunction structure is of a flocculent structure, and the size of the heterojunction structure is 25-40 nm.

2. The method of preparing the non-carbon based low-cost oxygen evolution catalyst of claim 1, characterized by the steps of:

(1)Co₃O₄preparation of TiN catalyst: dissolving cobalt acetate in a solvent A, adding nano titanium nitride and ammonia water, reacting at 70-90 ℃ for 10-15 h, alternately and repeatedly cleaning the centrifuged product with ethanol and water for 3-5 times, and drying; calcining the dried product to finally obtain a product Co₃O₄A TiN catalyst;

the cobalt acetate: nano titanium nitride: the mass ratio of ammonia water is 1-4: 1: 2-12;

the w/v of the cobalt acetate, the nano titanium nitride and the ammonia water in the solvent A is 4-32 percent, g/ml;

the solvent A is absolute ethyl alcohol and water with the volume ratio of 0-25: 25-0;

(2)[email protected]₂preparation of the catalyst: under the protection of flowing inert gas B, Co is added₃O₄Putting TiN catalyst and sodium hypophosphite into a tubular furnace for selective phosphating treatment to finally prepare CoP @ TiO₂A catalyst;

said Co₃O₄A TiN catalyst: the mass ratio of the sodium hypophosphite is 2: 2.5 to 10;

the inert gas B is one of nitrogen and argon;

the flow rate of the inert gas B is 0.1-0.5L/min.

3. The method of claim 2, wherein: the drying temperature in the step (1) is 50-80 ℃, and the time is more than 24 hours.

4. The production method according to claim 2 or 3, characterized in that: the calcination temperature in the step (1) is 300-500 ℃, the heating rate is 2-5 ℃/min, and the time is 2-5 h.

Technical Field

The invention belongs to the technical field of hydrogen production by water electrolysis through an anion exchange membrane, and relates to a non-carbon-based low-cost oxygen evolution catalyst and a preparation method thereof.

Background

With the increasing severity of global environment and energy problems, new energy sources such as wind energy, water energy, solar energy, biological energy, hydrogen energy and the like are widely concerned. Among them, the green energy represented by hydrogen energy has the characteristics of cleanness, high efficiency, environmental friendliness and the like. At present, the industrial application is mainly to produce hydrogen by using fossil fuel, which obviously cannot avoid the problems of non-regeneration of fossil energy, environmental hazard and the like. The technology of producing hydrogen by electrolyzing water using water as raw material has become the main research direction at present. Water is almost inexhaustible and inexhaustible as a resource existing in large quantities on the earth. The product of hydrogen production by water electrolysis is single and has no harm to the environment.

The hydrogen production by water electrolysis through an anion exchange membrane is a novel method for producing hydrogen by water electrolysis, and a plurality of research institutions and universities actively participate in the research mainly because of low cost and high performance. Compared with alkaline electrolysis water and proton exchange membrane electrolysis water, the anion exchange membrane electrolysis water combines the advantages of the alkaline electrolysis water and the proton exchange membrane electrolysis water, so that high-purity hydrogen can be prepared, and a non-noble metal catalyst can be used as a cathode and anode catalyst, thereby obviously reducing the cost. The core component of the water electrolysis hydrogen production equipment with the anion exchange membrane is the membrane electrode, wherein the membrane electrode consists of a cathode and anode catalyst layer and an anion exchange membrane, the cathode and anode catalyst layer consists of a catalyst, and the existing catalyst has the problems of poor performance and stability, so that the search for a catalyst with excellent performance and stability and low cost is one of the focuses of the existing concern.

Disclosure of Invention

The invention aims to improve the performance and stability of water electrolysis hydrogen production by anion exchange membranes and reduce the equipment cost, and provides a preparation method of a non-carbon-based low-cost oxygen evolution catalyst, which comprises the following steps: co with excellent performance and stability is synthesized₃O₄TiN catalyst, and then CoP @ TiO is prepared by vapor deposition selective phosphating method on the basis₂A catalyst. Is made ofThe prepared catalyst has better performance and stability, and can be applied to a cell for producing hydrogen by electrolyzing water through an anion exchange membrane.

The technical scheme of the invention is as follows:

a non-carbon based low-cost oxygen evolution catalyst, namely CoP @ TiO₂The catalyst has the following structure:

[email protected]₂the catalyst mainly comprises CoP and TiO₂Two components, CoP and TiO₂Forming a heterojunction structure, wherein the appearance of the heterojunction structure is of a flocculent structure, and the size of the heterojunction structure is 25-40 nm.

A preparation method of a non-carbon-based low-cost oxygen evolution catalyst comprises the following steps:

（1）Co₃O₄preparation of TiN catalyst: dissolving cobalt acetate in a solvent A, adding nano titanium nitride and ammonia water, reacting at 70-90 ℃ for 10-15 h, alternately and repeatedly cleaning the centrifuged product for 3-5 times by using industrial ethanol and pure water, and drying in an oven. Calcining the dried product in a muffle furnace to finally obtain a product Co₃O₄A TiN catalyst;

the cobalt acetate: nano titanium nitride: the mass ratio of ammonia water is 1-4: 1: 2-12;

the w/v (g/ml) of the cobalt acetate, the nano titanium nitride and the ammonia water in the solvent A is 4-32%;

the solvent A is a mixed solution of absolute ethyl alcohol and pure water;

the solvent A comprises absolute ethyl alcohol: the volume ratio of the pure water is 0-25: 25-0;

（2）[email protected]₂preparation of the catalyst: under the protection of flowing inert gas B, Co is added₃O₄Putting TiN catalyst and sodium hypophosphite into a tubular furnace for selective phosphating treatment to finally prepare CoP @ TiO₂A catalyst;

said Co₃O₄A TiN catalyst: the mass ratio of sodium hypophosphite is 2: 2.5 to 10;

the inert gas B is one of nitrogen and argon;

the flow rate of the inert gas B is 0.1-0.5L/min;

said Co₃O₄Drying the TiN catalyst at the temperature of 50-80 ℃ for more than 24 hours; said Co₃O₄The calcination temperature of the TiN catalyst in a muffle furnace is 300-500 ℃, the heating rate is 2-5 ℃/min, and the time is 2-5 h; the CoP @ TiO₂The calcination temperature of the catalyst in a tubular furnace is 300-500 ℃, the heating rate is 2-5 ℃/min, and the time is 2-5 h.

The invention has the beneficial effects that:

(1) a series of catalysts are prepared by regulating and controlling the proportion of the catalyst precursor and the degree of phosphorization, and the performance and stability of the prepared catalyst can be controlled.

(2) The prepared catalyst has excellent performance and stability, and the preparation method is simple and has lower cost.

（3）[email protected]₂The catalyst has better performance and stability than noble metal catalyst in the upper cell test, and the hydrogen production rate is stable.

Drawings

FIG. 1 shows different degrees of phosphating CoP @ TiO₂XRD test pattern of catalyst.

FIG. 2 is CoP @ TiO₂SEM test pattern of catalyst.

FIG. 3 is 2:5 degree of phosphorization CoP @ TiO₂XRD test pattern of catalyst.

FIG. 4 is 2:10 degree of phosphorylation CoP @ TiO₂XRD test pattern of catalyst.

FIG. 5 is an XRD test pattern of the CoP @ TiO2 catalyst prepared in example 3.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1

（1）Co₃O₄Preparation of TiN catalyst: dissolving 1 g of cobalt acetate in 25 ml of pure water, adding 0.5 g of nano titanium nitride and 2 ml of ammonia water, performing ultrasonic treatment, pouring into a round-bottom flask, reacting for 10 hours at 80 ℃, alternately and repeatedly cleaning the centrifuged product for 3 times by using industrial ethanol and pure water, and drying in an oven at 60 ℃ for 24 hours. The dried product was muffle at 300 deg.CCalcining for 2 h in a furnace with the heating rate of 5 ℃/min to finally prepare Co₃O₄A TiN catalyst;

（2）[email protected]₂the preparation of the catalyst comprises the step of adding 0.2 g of Co under the protection of 0.1L/min argon₃O₄Putting TiN catalyst and 0.5 g sodium hypophosphite into a 300 ℃ tubular furnace with the heating rate of 2 ℃/min for selective phosphating for 2 h to finally prepare CoP @ TiO₂A catalyst;

CoP @ TiO obtained in this example₂The structure of the catalyst was demonstrated by cell testing (FIG. 3), CoP @ TiO prepared in this example₂The catalyst is in a KOH solution of 1 mol/L at 50 ℃ and at the voltage of 2V, the current density is 800 mA/cm². At 400 mA/cm²The lower stability can reach more than 100 h.

Example 2

（1）Co₃O₄Preparation of TiN catalyst: dissolving 1.5 g of cobalt acetate in 25 ml of pure water, adding 0.5 g of nano titanium nitride and 3 ml of ammonia water, performing ultrasonic treatment, pouring into a round-bottom flask, reacting for 10 hours at 80 ℃, alternately and repeatedly cleaning the centrifuged product for 3 times by using industrial ethanol and pure water, and drying in an oven at 60 ℃ for 24 hours. Calcining the dried product in a muffle furnace at 300 ℃ for 2 h at the heating rate of 5 ℃/min to finally obtain Co₃O₄A TiN catalyst;

（2）[email protected]₂the preparation of the catalyst comprises the step of adding 0.2 g of Co under the protection of 0.1L/min of argon₃O₄Putting TiN catalyst and 1 g sodium hypophosphite into a 300 ℃ tubular furnace with the heating rate of 2 ℃/min for selective phosphating for 2 h to finally prepare CoP @ TiO₂A catalyst;

CoP @ TiO obtained in this example₂The structure of the catalyst was demonstrated by cell testing (FIG. 4), CoP @ TiO prepared in this example₂The catalyst is in a KOH solution of 1 mol/L at 50 ℃ and under the voltage of 2V, the current density is 1000 mA/cm². At 400 mA/cm²The lower stability can reach more than 100 h.

Example 3

（1）Co₃O₄Preparation of TiN catalyst: 1.5 g of cobalt acetate was dissolved in 2Adding 0.5 g of nano titanium nitride and 3 ml of ammonia water into 5 ml of pure water, performing ultrasonic treatment, pouring the mixture into a round-bottom flask, reacting for 10 hours at 80 ℃, alternately and repeatedly cleaning the centrifuged product for 3 times by using industrial ethanol and pure water, and drying in an oven at 60 ℃ for 24 hours. Calcining the dried product in a muffle furnace at 300 ℃ for 2 h at the heating rate of 5 ℃/min to finally obtain Co₃O₄A TiN catalyst;

（2）[email protected]₂the preparation of the catalyst comprises the step of adding 0.2 g of Co under the protection of 0.1L/min of argon₃O₄Putting TiN catalyst and 0.25 g sodium hypophosphite into a 300 ℃ tubular furnace with the heating rate of 2 ℃/min for selective phosphating for 2 h to finally prepare CoP @ TiO₂A catalyst;

CoP @ TiO obtained in this example₂The structure of the catalyst was demonstrated by cell testing (FIG. 5), CoP @ TiO prepared in this example₂The catalyst is in a KOH solution of 1 mol/L at 50 ℃ and under the voltage of 2V, the current density is 750 mA/cm². At 400 mA/cm²The lower stability can reach more than 100 h.