Decoupling fast hydrogen oxidation reaction on a tandem electrocatalyst
Wei Guo, Guoqiang Zhao, Ziang Sun, Bingxing Zhang, Dongyue Xin, Mingxia Gao, Yongfeng Liu, Zhongbin Zhuang, Hai‐Wei Liang, Hongge Pan, Wenping Sun
Abstract
The hydrogen oxidation reaction (HOR) shows fast kinetics in proton exchange membrane fuel cells (PEMFCs), and has not drawn intense attention. Here, we propose a tandem electrocatalysis concept, decoupling HOR on two independent active sites for accelerated kinetics. As a proof-of-concept application, a Ru-based tandem HOR catalyst is designed, with Ru nanoclusters decorated with Pt single atoms. Experimental and theoretical studies suggest that H2 dissociation occurs at Ru sites, and then the produced H species migrate to Pt sites followed by the desorption of H+. The strong Ru-H interaction promotes the H2 dissociation step, while the optimum Pt-H interaction ensures the fast desorption, thereby substantially enhancing the HOR kinetics. In H2–O2 fuel cells, this catalyst enables a peak power density of 1.91 W cm−2 and a high anodic mass activity of 23.12 A mg−1 at 0.9 ViR-free with an ultralow noble metal loading of 5 μg cm−2. This work advances the development of low-cost anode catalysts for fuel cells and provides more insight into understanding hydrogen electrocatalysis. Developing low-Pt or Pt-free electrocatalysts is critical for lowering the cost of proton exchange membrane fuel cells. Here, the authors report a low-cost and high performance tandem catalyst, with Ru nanoclusters decorated with Pt single atoms, for the anodic hydrogen oxidation reaction.