Implanting oxophilic metal in PtRu nanowires for hydrogen oxidation catalysis

Abstract

Bimetallic PtRu are promising electrocatalysts for hydrogen oxidation reaction in anion exchange membrane fuel cell, where the activity and stability are still unsatisfying. Here, PtRu nanowires were implanted with a series of oxophilic metal atoms (named as i-M-PR), significantly enhancing alkaline hydrogen oxidation reaction (HOR) activity and stability. With the dual doping of In and Zn atoms, the i-ZnIn-PR/C shows mass activity of 10.2 A mg_Pt+Ru⁻¹ at 50 mV, largely surpassing that of commercial Pt/C (0.27 A mg_Pt⁻¹) and PtRu/C (1.24 A mg_Pt+Ru⁻¹). More importantly, the peak power density and specific power density are as high as 1.84 W cm⁻² and 18.4 W mg_Pt+Ru⁻¹ with a low loading (0.1 mg cm⁻²) anion exchange membrane fuel cell. Advanced experimental characterizations and theoretical calculations collectively suggest that dual doping with In and Zn atoms optimizes the binding strengths of intermediates and promotes CO oxidation, enhancing the HOR performances. This work deepens the understanding of developing novel alloy catalysts, which will attract immediate interest in materials, chemistry, energy and beyond.

Designing an efficient electrocatalyst of hydrogen oxidation reaction is highly critical for anion exchange membrane fuel cells. Here the authors report implanting oxophilic metal atoms in PtRu nanowires to significantly improve the mass activity, stability, and resistance to CO-poisoning for hydrogen oxidation.