Enhanced oxygen reduction reaction activity through spillover effect by Pt–Y(OH) 3/C catalyst in direct methanol fuel cells

Abstract

Dynamic spillover of metal oxide aided by yttrium hydroxide through its altervalent nature is utilized to develop a new carbon supported Pt–Y(OH) 3 hybrid catalyst with varying Pt:Y atomic ratio of 1:1, 2:1 and 3:1 and characterized by X-Ray diffraction and Transmission electron microscopy techniques. Pt–Y/C catalysts exhibit significant improvement in oxygen reduction reaction (ORR) over commercial Pt/C. The effects of composition toward ORR with and without methanol have been studied. Among the various Pt–Y(OH) 3/C catalysts, the one with Pt to Y in 3:1 atomic ratio shows the highest activity for ORR in aqueous HClO 4 solution without methanol while the one with Pt to Y in 2:1 atomic ratio shows the maximum activity for ORR in presence of methanol. A direct methanol fuel cell (DMFC) employing carbon-supported Pt–Y(OH) 3 as the cathode catalyst delivers a peak-power density of 105 mW/cm 2 at 70 °C as compared to a peak-power density of 64 mW/cm 2 obtained with the DMFC employing carbon-supported Pt catalyst operating under similar conditions.