Effects of RuO2 Content in Pt/RuO2/CNTs Nanocatalyst on the Electrocatalytic Oxidation Performance of Methanol

A novel Pt/RuO2/CNTs anodic catalyst was prepared for direct methanol fuel cells (DMFC). Compared to Pt/CNTs with the same Pt loading, the activity of Pt/RuO2/CNTs for electrocatalytic oxidation of methanol is 3 times higher. The electrocatalytic activity of Pt/RuO2/CNTs with different RuO2 contents was investigated by cyclic voltammetry. It was observed that the electrocatalytic performance of Pt/RuO2/CNTs was strongly dependent on the RuO2 content. The Pt/RuO2/CNTs catalyst with 15% Pt and 9.5% RuO2 exhibits the best electrocatalytic methanol oxidation activity. The specific capacitance change of RuO2/CNTs, determined by the matching degree of proton conductivity and electron transfer, is the main reason for the change of electrocatalytic methanol oxidation activity of Pt/RuO2/CNTs with different RuO2 contents. The novel electrocatalyst design concept based on capacitance may be very useful in designing electrocatalysts for DMFC.