Dual synergetic catalytic effects boost hydrogen electric oxidation performance of Pd/W₁₈O₄₉

Developing anode catalysts of substantially enhanced activity for hydrogen oxidation reaction (HOR) and anti-CO poisoning performance is of great importance for the application of proton exchange membrane fuel cells (PEMFCs). Herein, we report Pd cluster in situ decorated urchin-like W₁₈O₄₉ (WO_2.72) electrocatalysts by a photo-reduction method for high performance HOR. The synthesized Pd-WO_2.72-L composite of low loading amount of 0.44 wt.% Pd by Xenon light reduction exhibits markedly high HOR catalytic activity and stability in 0.5 M H₂SO₄, and the specific HOR current density and mass activity of Pd-WO_2.72-L are ~ 1.5 and ~ 80 times those of 20 wt.% Pt/C catalyst, respectively. Moreover, excellent anti-CO poisoning ability has also been obtained. The excellent HOR activity and anti-CO poisoning performance of Pd-WO_2.72-L have been discussed mainly in terms of the dual synergetic catalytic effects between Pd and WO_2.72: Pd activation to Pd^δ+ by the electron transfer from Pd to W promotes the hydrogen adsorption and activation to H* species, which results in largely elevated HOR activity; Pd degradation due to the CO poisoning is effectively prevented by WO_2.72, which is responsible for the excellent CO-tolerance performance.