Preparation and characterization of anti-flooding functional Pt/C catalyst for PEMFC

Abstract

The important reason of the reduction of the catalytic performance of Pt/C catalyst is carbon carrier corrosion. The risk of oxgen flooding in proton-exchange membrane fuel cellsis also increased by hydrophilicity of this catalyst. The Pt/C catalyst was subsequently reduced using hydrazine hydrate to make Pt/C corrosion resistant and anti-flooding. Comparison by infrared spectra of absorption peaks shows the increased number of oxygen-containing functional groups in the XC-72 carbon surface treated with hydrogen peroxide. Its measured contact angle is less than that of untreated XC-72 carbon. Reduction of oxidized XC-72 carbon with hydrazine hydrate shows that the contact angle is increased by 22.4° compared with that of the oxidized XC-72 carbon, indicating anti-flooding enhancement. As shown in the specific surface area measurement, the specific surface area of XC-72 is reduced by the hydrogen peroxide treatment but its mespopore ratio is increased, which favors the carrier load Pt. The anti-flooding of Pt/C catalyst after reduction with hydrazine hydrate is stronger than that before reduction, indicating an increase in contact angle by 6.2°. After 2000 cycles of cyclic voltammetry, the electrochemical specific surface loss is decreased and the durability is improved for the reduced Pt/C catalyst by hydrazine hydrate.

Keywords

• proton exchange membrane fuel cell
• catalyst
• anti-flooding
• hydrogen peroxide
• hydrazine hydrate