阅读说明：本技术 一种质子交换膜燃料电池双元合金催化剂的高温制备方法 (High-temperature preparation method of binary alloy catalyst of proton exchange membrane fuel cell ) 是由 华秋茹 张义煌 张明 刘倩 包喆宇 陈杰 李刚 于 2020-05-15 设计创作，主要内容包括：本发明属于新能源材料与应用技术领域,特别涉及到一种质子交换膜燃料电池双元合金催化剂的高温制备方法。本发明的制备方法包括以下步骤：(1)将过渡金属前驱体溶液与铂碳催化剂悬浮液进行混合并搅拌,充分分散；(2)将沉淀剂溶液和还原剂溶液加入步骤(1)中分散后的混合液中,调节混合液的pH值为9-13,沉淀完全后离心或者压滤洗涤数次,充分干燥后得到催化剂前驱体粉末；(3)将催化剂前驱体粉末高温焙烧,降温后酸洗,干燥后得到催化剂粉末。本发明使用过渡金属元素与铂催化剂形成双元合金催化剂,能够降低催化剂的成本,过渡金属与铂形成合金后,使得铂的晶格收缩,降低表面对氧气的吸附能,从而提高氧还原反应的催化活性。(The invention belongs to the technical field of new energy materials and application, and particularly relates to a high-temperature preparation method of a binary alloy catalyst of a proton exchange membrane fuel cell. The preparation method comprises the following steps: (1) mixing and stirring the transition metal precursor solution and the platinum-carbon catalyst suspension liquid, and fully dispersing; (2) adding a precipitant solution and a reducing agent solution into the mixed solution dispersed in the step (1), adjusting the pH value of the mixed solution to 9-13, performing centrifugal or filter pressing washing for a plurality of times after complete precipitation, and fully drying to obtain catalyst precursor powder; (3) and roasting the catalyst precursor powder at high temperature, cooling, pickling and drying to obtain the catalyst powder. The invention uses the transition metal element and the platinum catalyst to form the binary alloy catalyst, which can reduce the cost of the catalyst, and after the transition metal and the platinum form the alloy, the crystal lattice of the platinum is shrunk, the adsorption energy of the surface to oxygen is reduced, thereby improving the catalytic activity of the oxygen reduction reaction.)

1. A high-temperature preparation method of a binary alloy catalyst of a proton exchange membrane fuel cell is characterized by comprising the following steps:

(1) mixing and stirring a transition metal precursor solution with the concentration of 0.01-5mol/L and a platinum-carbon catalyst suspension liquid, and fully dispersing;

(2) adding a precipitator solution with the concentration of 0.01-10mol/L and a reducing agent solution into the mixed solution dispersed in the step (1), adjusting the pH value of the mixed solution to 9-13, performing centrifugal or filter pressing washing for a plurality of times after complete precipitation, and fully drying to obtain catalyst precursor powder;

(3) and (2) roasting the catalyst precursor powder at the high temperature of 900 ℃ for 0.5-4h in the protective gas atmosphere at 300-4 ℃, cooling after roasting, adding an acid solution with the concentration of 0.01-5mol/L after cooling, centrifuging or filter-pressing and washing for a plurality of times, and fully drying to obtain the catalyst powder.

2. The high-temperature preparation method of the binary alloy catalyst for the proton exchange membrane fuel cell according to claim 1, wherein the transition metal precursor in the step (1) is one or more soluble salts of cobalt, nickel, iron or copper.

3. The high-temperature preparation method of the binary alloy catalyst for the proton exchange membrane fuel cell as recited in claim 1, wherein the transition metal precursor in the step (1) is a soluble salt of cobalt, nickel or copper, and comprises cobalt nitrate, cobalt chloride, cobalt acetate, nickel nitrate, nickel sulfate, nickel chloride or copper sulfate.

4. The high temperature preparation method of the PEM fuel cell binary alloy catalyst according to claim 1, wherein the solvent used for dispersing the Pt-C catalyst in the Pt-C catalyst suspension in step (1) is water and/or ethylene glycol, and the mass ratio of the Pt-C catalyst to the solvent is 1/500-1/40.

5. The high-temperature preparation method of the binary alloy catalyst for the proton exchange membrane fuel cell according to claim 1, wherein the precipitant solution in the step (2) is a mixed solution of one or more of sodium hydroxide, sodium carbonate or ammonia water.

6. The high-temperature preparation method of the binary alloy catalyst for the proton exchange membrane fuel cell according to claim 1, wherein the reducing agent in the step (2) is a mixed solution of one or more of ethylene glycol, sodium formate or sodium sulfite, and the molar ratio of the reducing agent to the transition metal is 0:1-100: 1.

7. The high-temperature preparation method of the binary alloy catalyst for the proton exchange membrane fuel cell according to claim 1, wherein the introduced protective gas in the roasting process of the catalyst precursor in the step (3) is one or more of nitrogen, hydrogen or argon.

8. The high temperature preparation method of the binary alloy catalyst for the proton exchange membrane fuel cell according to claim 1, wherein the aqueous solution of hydrochloric acid, sulfuric acid or nitric acid is adopted when acid washing is performed after the roasting in the step (3), and the concentration range is 0.01-5 mol/L.

9. The high-temperature preparation method of the binary alloy catalyst for the proton exchange membrane fuel cell according to claim 1, wherein the temperature rise rate during the high-temperature roasting in the step (3) is controlled to be 1-20 ℃/min.

10. The high-temperature preparation method of the binary alloy catalyst for the proton exchange membrane fuel cell according to claim 1, wherein the drying temperature of the catalyst precursor in the step (2) and the drying temperature of the catalyst in the step (3) are 30-90 ℃.

Technical Field

The invention belongs to the technical field of new energy materials and application, and particularly relates to a high-temperature preparation method of a binary alloy catalyst of a proton exchange membrane fuel cell.

Background

The proton exchange membrane fuel cell has the advantages of cleanness, high efficiency, high power density and the like, is a research hotspot in recent years, has wide application prospect, but the cost and the service life of the proton exchange membrane fuel cell are still the main problems restricting the industrialization of the proton exchange membrane fuel cell. Among other things, the stability and price of the catalyst directly determine the durability and cost of the fuel cell. Therefore, it is necessary to develop a fuel cell catalyst with high activity, low cost and high stability.

At present, the catalyst for the fuel cell is mainly a platinum catalyst, the price of platinum is high, the resource is limited, the cost of the pure platinum catalyst is high and accounts for about 40 percent of the cost of the fuel cell; and the catalytic activity of the pure platinum catalyst to the cathode side oxygen reduction reaction is limited because the adsorption energy of the pure platinum surface to oxygen is larger. In the report of preparing the alloy catalyst by the existing high-temperature heat treatment, the alloy particles grow up by the high-temperature treatment, and the catalytic activity of the catalyst particles is greatly influenced by the overlarge particle size. Meanwhile, in the operation process of the battery, catalyst particles are agglomerated and dissolved, so that the performance of the battery is reduced, the stability is reduced, and the service life is shortened.

Disclosure of Invention

The invention aims to solve the technical problem of providing a high-temperature preparation method of a binary alloy catalyst of a proton exchange membrane fuel cell aiming at the defects of the prior art. The preparation method of the invention can reduce the consumption of noble metal platinum of the fuel cell catalyst, improve the catalytic activity of oxygen reduction, reduce the cost of the fuel cell and improve the stability of the catalyst.

In order to solve the technical problems, the invention adopts the technical scheme that: a high-temperature preparation method of a binary alloy catalyst of a proton exchange membrane fuel cell comprises the following steps:

(1) mixing and stirring a transition metal precursor solution with the concentration of 0.01-5mol/L and a platinum-carbon catalyst suspension liquid, and fully dispersing;

(2) adding a precipitator solution with the concentration of 0.01-10mol/L and a reducing agent solution into the mixed solution dispersed in the step (1), adjusting the pH value of the mixed solution to 9-13, performing centrifugal or filter pressing washing for a plurality of times after complete precipitation, and fully drying to obtain catalyst precursor powder;

(3) and (2) roasting the catalyst precursor powder at the high temperature of 900 ℃ for 0.5-4h in the protective gas atmosphere at 300-4 ℃, cooling after roasting, adding an acid solution with the concentration of 0.01-5mol/L after cooling, centrifuging or filter-pressing and washing for a plurality of times, and fully drying to obtain the catalyst powder.

In the step (1), the transition metal precursor is one or more soluble salts of cobalt, nickel, iron or copper.

The transition metal precursor in the step (1) is soluble salt of cobalt, nickel or copper, and comprises cobalt nitrate, cobalt chloride, cobalt acetate, nickel nitrate, nickel sulfate, nickel chloride or copper sulfate.

The solvent used for dispersing the platinum-carbon catalyst in the platinum-carbon catalyst suspension in the step (1) is water and/or ethylene glycol, and the mass ratio of the platinum-carbon catalyst to the solvent is 1/500-1/40.

And (3) the precipitant solution in the step (2) is one or more of sodium hydroxide, sodium carbonate or ammonia water.

In the step (2), the reducing agent is one or a mixture of more of ethylene glycol, sodium formate or sodium sulfite, and the molar ratio of the reducing agent to the transition metal is 0:1-100: 1.

And (3) introducing one or more of nitrogen, hydrogen or argon as protective gas in the roasting process of the catalyst precursor.

And (3) after roasting is finished, adopting an aqueous solution of hydrochloric acid, sulfuric acid or nitric acid when acid washing is carried out, wherein the concentration range is 0.01-5 mol/L.

And (3) controlling the heating rate to be 1-20 ℃/min during high-temperature roasting.

The drying temperature of the catalyst precursor in the step (2) and the drying temperature of the catalyst in the step (3) are 30-90 ℃.

Compared with the prior art, the invention has the following advantages:

1. the invention uses transition metal element and platinum catalyst to form binary alloy catalyst, the transition metal has low price, and the consumption of platinum is reduced, thereby effectively reducing the cost of catalyst.

2. After the transition metal selected by the invention forms alloy with platinum, the crystal lattice of the platinum is contracted, the adsorption energy of the surface to oxygen is reduced, and the catalytic activity of the oxygen reduction reaction is improved.

3. The adoption of the high-temperature heat treatment process and the addition of the precipitator and the reducing agent can effectively inhibit the growth of alloy particles in the high-temperature process, and the unalloyed transition metal elements are less and can be removed by acid washing, so that the catalyst prepared by the method has the advantages of small particle size, high alloying degree, high catalytic activity and stability.

4. The invention uses environment-friendly raw materials, does not use reducing agents such as sodium borohydride or hydrazine hydrate, has relatively simple process and equipment, and is easy to realize large-scale production.

Drawings

FIG. 1 is a flow chart of the preparation process of the binary alloy catalyst of the proton exchange membrane fuel cell of the invention.

FIG. 2 is an X-ray diffraction pattern of catalysts prepared in examples 2-5 of the present invention.

FIG. 3 is a cyclic voltammogram of the catalyst prepared in example 1 of the present invention.

Fig. 4 is an oxygen reduction polarization curve of the catalyst prepared in example 2 and a commercial platinum carbon catalyst.

Figure 5 is an oxygen reduction curve of the catalyst prepared in example 6 versus a commercial platinum cobalt alloy carbon catalyst.

Detailed Description

The technical problem to be solved by the invention can be realized by the following technical scheme: a high-temperature preparation method of a proton exchange membrane fuel cell binary alloy catalyst comprises the steps of catalyst precursor treatment, catalyst high-temperature reduction alloying, catalyst acid pickling treatment and the like, and concretely, as shown in figure 1, a transition metal precursor solution is added into a platinum-carbon catalyst suspension liquid dispersed by a solvent, after full stirring and dispersion, a precipitator and a reducing agent solution with certain concentration are added into the suspension liquid, after complete reaction, the suspension liquid is centrifuged or filter-pressed and washed for several times, and dried into catalyst precursor powder at a certain temperature; and putting the precursor powder into a tube furnace, roasting at a high temperature for a period of time, cooling, taking out, adding an acid solution with a certain concentration, centrifuging or filter-pressing, washing for a plurality of times, and drying to obtain the catalyst powder.

The technical solution of the present invention will be further described with reference to the following embodiments and accompanying drawings.