Effect of RuO 2· xH 2O in anode on the performance of direct methanol fuel cells

Abstract

The effect of hydrous RuO 2 (RuO 2· xH 2O) in anode on the performance of direct methanol fuel cells (DMFCs) was examined by voltammetry, methanol stripping analysis, electrochemical impedance spectroscopy, polarization measurement and chronopotentiometry. The results showed that, compared with the DMFC with conventional structures, the dynamic response and quasi-steady state performance of the RuO 2· xH 2O-introduced DMFCs were significantly improved. The DMFC with RuO 2· xH 2O layer (ROL) sandwiched between anode catalyst layer and gas diffusion layer exhibited better quasi-steady state performance than those either with ROL sandwiched between anode catalyst layer and electrolyte membrane or with RuO 2· xH 2O uniformly distributed in anode catalyst layer. The maximum power density of the DMFC with this novel structure was 16% higher than the DMFC with the conventional structure. Moreover, the dynamic response of this RuO 2· xH 2O-introduced cell was more stable during 250-hour of operation when compared with that of the conventional cell.