Search

CN-121983597-A - Preparation method of conductive oxide supported palladium-ethanol fuel cell anode catalyst

CN121983597ACN 121983597 ACN121983597 ACN 121983597ACN-121983597-A

Abstract

The invention belongs to the field of fuel cells, and relates to a preparation method of an anode catalyst of a conductive oxide supported palladium-ethanol fuel cell, wherein the catalyst is a Pd/c-TiO 2 @MoO 3 catalyst, and the preparation method comprises the following steps of mixing TiO 2 and a molybdenum source, roasting to obtain TiO 2 @MoO 3 , and chemically reducing to obtain conductive c-TiO 2 @MoO 3 ; dispersing the catalyst, adding a palladium precursor for adsorption and reducing, washing and drying to obtain Pd/c-TiO 2 @MoO 3 anode catalyst, and then loading the catalyst on an electrode substrate for activation to obtain the working electrode. The method has the advantages of simple process and strong controllability, and the obtained catalyst has excellent conductivity and catalytic performance, can be used for catalyzing ethanol oxidation reaction by the anode of a direct ethanol fuel cell, and has good application prospect. The invention provides a novel and feasible solution for the stability problem of the anode catalyst of the direct ethanol fuel cell, and is expected to promote the industrialized application process of the direct ethanol fuel cell.

Inventors

  • ZOU HAI
  • XIONG WEI
  • ZHANG YONGJIA
  • LU XIANG
  • TAN DONGXIN
  • CHEN MENGYAO

Assignees

  • 重庆科技大学

Dates

Publication Date
20260505
Application Date
20260304

Claims (8)

  1. 1. A method for preparing an electrocatalyst, wherein the electrocatalyst is a Pd/c-TiO 2 @MoO 3 catalyst, the method comprising the steps of: S1, preparing a TiO 2 composite material TiO 2 @MoO 3 modified by MoO 3 , namely uniformly mixing TiO 2 with a molybdenum source, roasting at a set temperature, and cooling to obtain TiO 2 @MoO 3 ; S2, preparing a conductive c-TiO 2 @MoO 3 composite material, namely reducing the TiO 2 @MoO 3 composite material prepared in the step S1 to obtain a conductive c-TiO 2 @MoO 3 composite material; And S3, preparing a Pd/c-TiO 2 @MoO 3 catalyst, namely dispersing the conductive c-TiO 2 @MoO 3 composite material obtained in the step S2 in a solvent, adding a palladium precursor, stirring for adsorption, then adding a first reducing agent for reduction reaction, washing and drying to obtain the Pd/c-TiO 2 @MoO 3 catalyst.
  2. 2. The method according to claim 1, characterized in that: S1, the cooling is specifically natural cooling to 15-30 ℃, and/or In S1, the molybdenum source is selected from one or more of molybdenum trioxide, ammonium orthomolybdate, ammonium paramolybdate, ammonium tetramolybdate, molybdenum acetate and molybdenum formate, and/or In S1, the ratio of TiO 2 to the molybdenum source is 1:0.05-1:0.3 based on the calculation of completely converting the molybdenum source into MoO 3 , and/or the mass ratio of TiO 2 ：MoO 3 is 1:0.05-1:0.3 In S1, the mixing method is one or more selected from ball milling, grinding, soaking, evaporating, ultrasonic precipitation, and/or In S1, the roasting temperature is 300-500 0 C, and/or In S1, the roasting time is 1-10 h, and/or In S3, the palladium precursor is sodium chloropalladate and/or S3, the temperature of the stirring adsorption is 15-30 ℃, and/or S3, the stirring and adsorbing time is 0.5-5h, and/or S3, the temperature of the reduction reaction is 15-30 ℃, and/or S3, the time of the reduction reaction is 0.1-2h, and/or S3, the solvent is selected from one or more of water, methanol, ethanol and glycol, and/or In S3, the first reducing agent is selected from one or more of sodium borohydride and hydrazine hydrate, and/or In S3, the amount of the substances added in the first reducing agent is 1 to 100 times of the amount of the palladium atomic substances, and/or In S3, the Pd loading amount is 5-20% of the mass of the Pd/c-TiO 2 @MoO 3 composite material.
  3. 3. The method of claim 2, wherein the step of determining the position of the substrate comprises, In S2, the reduction treatment method is a solid-liquid phase chemical reduction method, which is specifically characterized in that TiO 2 @MoO 3 composite material is uniformly dispersed in a solvent by ultrasonic, a second reducing agent is slowly added under the stirring condition at the temperature of 15-30 ℃, the stirring reaction is continuously carried out for 0.5-5h, and then the C-TiO 2 @MoO 3 is obtained by washing and drying.
  4. 4. The method of claim 3, wherein the step of, The second reducing agent is selected from one or more of sodium borohydride and hydrazine hydrate, and/or The addition amount of the second reducing agent is 0.1-10 times of the amount of the molybdenum atomic substances.
  5. 5. An anode working electrode, characterized in that the preparation method comprises: Dispersing the Pd/c-TiO 2 @MoO 3 catalyst obtained by the method in any one of claims 1-4 in a mixed solution of water and ethanol to form a uniform suspension, loading the suspension on the surface of an electrode substrate, drying and activating to obtain the anode working electrode.
  6. 6. The anode working electrode of claim 5 wherein, In the mixed solution, the volume ratio of water to ethanol is 1:2-2:1, and/or The suspension dispersing method is ultrasonic and/or The suspension is loaded on the surface of the electrode substrate by one or more methods selected from dripping, spin coating and spray coating, and/or The concentration of Pd/c-TiO 2 @MoO 3 in the suspension is 0.1-10 mg/mL, and/or The electrode substrate is selected from one of a glassy carbon electrode, a carbon paper electrode and foam nickel.
  7. 7. Use of a Pd/c-TiO 2 @MoO 3 catalyst obtainable by a process according to any one of claims 1 to 4 or an anode working electrode according to claim 5 or 6 in the preparation of a battery.
  8. 8. Use according to claim 7, characterized in that the cell is a direct ethanol fuel cell.

Description

Preparation method of conductive oxide supported palladium-ethanol fuel cell anode catalyst Technical Field The invention belongs to the field of fuel cells, and relates to a preparation method of an anode catalyst of a conductive oxide supported palladium-ethanol fuel cell. Background A direct ethanol fuel cell (Direct Ethanol Fuel Cell, DEFC) is a galvanic device that converts chemical energy in ethanol into electrical energy. The DEFC uses the ethanol which can be regenerated biologically as the fuel, and the energy conversion process is not limited by the Carnot cycle in the heat engine, thus being hopeful to realize a clean and efficient energy conversion process. The DEFC operation involves mainly two key reactions, ethanol oxidation at the anode (Ethanol Oxidation Reaction, EOR) and oxygen reduction at the cathode. However, the commercialization of DEFC is still hampered by efficiency and cost, one of which is the development of highly efficient and stable electrocatalytic EOR catalysts. The support is an important component of EOR electrocatalysts, and is one of the key factors in improving catalyst performance, which not only provide anchor sites for catalytic activity centers, but also affect the kinetics of electron transport and surface reactions. The common electrocatalyst carrier is a carbon material carrier, and carbon materials such as activated carbon, graphene, carbon nanotubes and the like have the advantages of high conductivity, low price and the like, and are widely applied in the electrocatalytic process. However, in the anodic catalytic reaction, when a carbon-based material is used as a carrier, the carbon-based carrier itself is oxidized under the action of a long-time oxidation potential to damage the catalyst structure, resulting in a decrease in catalyst activity and stability. To address this problem, researchers have replaced carbon materials with other carrier materials. For example, the patent (patent number: CN 108550863B) named "preparation method of self-renewable ethanol fuel cell anode catalyst" modifies TiO 2 by silicon-based material to obtain f-TiO 2 as carrier, thus realizing good stability in EOR, and the patent (patent number: CN 115000434B) named "direct ethanol fuel cell electrocatalyst with functional carrier and preparation method thereof) promotes C-C fracture in ethanol oxidation by supporting platinum nano particles by AlTi@AlTiO x functional carrier, thus enhancing acid corrosion resistance and stability of EOR catalyst. From the results, it is expected that the stable oxide such as TiO 2 with acid and alkali resistance is modified to realize the improvement of EOR stability and activity as an electrocatalytic carrier. However, oxides such as TiO 2 have low conductivity types, and challenges exist in how to synthesize conductive metal oxide electrocatalytic supports for efficient, stable EOR. Disclosure of Invention Aiming at the problems that the anode catalyst of the direct ethanol fuel cell is unstable to operate under the oxidation potential for a long time and the conductivity of the oxide electrocatalytic carrier is insufficient, the preparation method of the anode catalyst of the conductive oxide supported palladium ethanol fuel cell, an anode working electrode prepared by the catalyst and the application of the catalyst or the anode working electrode in the preparation of the direct ethanol fuel cell are provided, and the aim is to solve the stability defect of the existing anode catalyst and improve the electrochemical performance of the cell. In order to achieve the above object, in a first aspect, there is provided a method for preparing an electrocatalyst, the electrocatalyst being a Pd/c-TiO 2@MoO3 catalyst, the method comprising the steps of: S1, preparing a TiO 2 composite material TiO 2@MoO3 modified by MoO 3, namely uniformly mixing TiO 2 with a molybdenum source, roasting at a set temperature, and cooling to obtain TiO 2@MoO3; S2, preparing a conductive c-TiO 2@MoO3 composite material, namely reducing the TiO 2@MoO3 composite material prepared in the step S1 to obtain a conductive c-TiO 2@MoO3 composite material; And S3, preparing a Pd/c-TiO 2@MoO3 catalyst, namely dispersing the conductive c-TiO 2@MoO3 composite material obtained in the step S2 in a solvent, adding a palladium precursor, stirring for adsorption, then adding a first reducing agent for reduction reaction, washing and drying to obtain the Pd/c-TiO 2@MoO3 catalyst. In some embodiments of the first aspect, in S1, the cooling is specifically natural cooling to 15-30 ℃, which may be, for example, 15 ℃, 16 ℃, 17 ℃, 18 ℃, 19 ℃, 20 ℃, 21 ℃, 22 ℃, 23 ℃, 24 ℃, 25 ℃, 26 ℃, 27 ℃, 28 ℃, 29 ℃, 30 ℃. In some embodiments of the first aspect, in S1, the molybdenum source is selected from one or more of molybdenum trioxide, ammonium orthomolybdate, ammonium paramolybdate, ammonium tetramolybdate, molybdenum acetate, molybdenum formate. In some embodiments of the first aspect, in S1, the rat