Electrochemical Deposition of Highly Catalytically Active Palladium Nanoparticles - Application to Methanol Fuel Cell Anodes and its Kinetic Studies

Abstract

Fuel cell technology is a green and promising energy source for the future generation. Amongst all fuel cells, methanol oxidation with very low overpotential at modified electrodes is important for understanding and developing methanol fuel cell anodes. Platinum (Pt) is a well-known catalyst for the methanol oxidation reaction. However, Pt is expensive and also methanol oxidation intermediates adsorbs very strongly onto its surface. In the present study, a less expensive and highly active electrocatalyst was developed using palladium (Pd) by simple electrochemical technique. The scanning electron microscope (SEM) displays that small sized nanoparticles are in the range of 4-8 nm. The prepared material shows excellent electrocatalytic activity with quite low overpotential at room temperature. In addition, to understand the kinetics, energy of activation was determined by studying the methanol oxidation reaction at different temperature. The onset potential decrease with increasing temperature implies that the kinetics of the process improves at elevated temperature. The lowest activation energy was found to be 20 kJ/mol which is almost comparable with many Pd based materials.