Pd2Sn [010] nanorods as a highly active and stable ethanol oxidation catalyst

Abstract

The development of highly active, low cost and stable electrocatalysts for direct alcohol fuel cells remains a critical challenge. While Pd₂Sn has been reported as an excellent catalyst for the ethanol oxidation reaction (EOR), here we present DFT analysis results showing the (100) and (001) facets of orthorhombic Pd₂Sn to be more favourable for the EOR than (010). Accordingly, using tri-n-octylphosphine, oleylamine (OLA) and methylamine hydrochloride as size and shape directing agents, we produced colloidal Pd₂Sn nanorods (NRs) grown in the [010] direction. Such Pd₂Sn NRs, supported on graphitic carbon, showed excellent performance and stability as an anode electrocatalyst for the EOR in alkaline media, exhibiting 3 times and 10 times higher EOR current densities than that of Pd₂Sn and Pd nanospheres, respectively. We associate this improved performance with the favourable faceting of the NRs.