Influences of Both Carbon Supports and Heat‐Treatment of Supported Catalyst on Electrochemical Oxidation of Methanol

Abstract

The effects of carbon supports for platinum‐ruthenium (Pt‐Ru) catalysts on anode performance of direct methanol fuel cells (DMFC) were investigated. Good polarization characteristics of the methanol electrode were obtained for a Pt‐Ru catalyst supported on an acetylene black with high specific surface area and a pore size distribution in the range of 3 to 8 nm. The performance of the methanol electrode increased with the increase in pore volume for the pore size distribution of 3 to 8 nm. Analyses of various carbon blacks and supported catalysts were carried out with several techniques: adsorption (Brunauer‐Emmett‐Teller (BET) and Barrett‐Joyner‐Halenda (BJH) methods), adsorption, transmission electron microscope, and scanning electron microscope observations. The effects of the heat‐treating temperature, time, and atmosphere on the polarization curves of the methanol electrodes with the acetylene black were investigated. The heat‐treatment in air at 370°C improved not only methanol oxidation but the durability of the Pt‐Ru catalyst.