Boosting fuel cell catalysis by surface doping of W on Pd nanocubes

The development of active and durable non-Pt electrocatalysts with well-defined microstructure is of great importance to both fuel cell applications and fundamental understanding. Herein, we report a surface-doping process to prepare well-defined W-doped Pd nanocubes with a tunable atomic percent of W from 0 to 1.5% by using the Pd nanocubes as seeds. The obtained 1.2%W-doped Pd nanocubes/C exhibited greatly enhanced electrocatalytic performance toward oxygen reduction reaction in alkaline media, presenting an enhancement factor of 4.7 in specific activity and 2.5 in mass activity compared to the activity of a commercial Pt/C catalyst. The downshift of the d-band center due to a negative charge transfer from W to Pd intrinsically accounts for such improvement in activity by weakening the adsorption of reaction intermediates. Also, the 1.2%W-doped Pd nanocubes/C showed superior catalytic properties for the ethanol oxidation reaction, showing great potential for serving as a bifunctional electrocatalyst in fuel cells. (C) 2018, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.