Jie Wang†, Xue Dong†, Jing Liu*, Wenzhen Li, Luke T Roling, Jianping Xiao*, Luhua Jiang*
Electrocatalysis & Nanomaterial Laboratory, College of Materials Science & Engineering, Qingdao University of Science & Technology, Qingdao, 266042, P.R. China.
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P.R. China.
Department of Chemical & Biological Engineering, Iowa State University, Ames, IA 50011-1098, Unites States.
ABSTRACT:
Developing low cost and robust hydrogen oxidation reaction (HOR) electrocatalysts is urgent for anion exchange membrane fuel cells (AEMFCs). Herein, we report an efficient Ni-based catalyst for HOR in alkaline electrolyte, which is featured with an ultrafine Ni nanoparticle (3.7 nm) core and an ultra-thin N-doped carbon shell (0.36 nm). The optimized catalyst exhibits both excellent activity (24.4 A g-1Ni @ ƞ=50mV and exchange current density of 38 µA cm-2Ni) and superior stability for the HOR. Theoretical calculation reveals that the d-band state of Ni encapsulated in ultrathin N-doped carbon shell is downshifted, with optimal binding energies with OHad and Had, leading to a low limiting energy pathway for HOR.
KEYWORDS: hydrogen oxidation reaction, anion exchange membrane fuel cell, Ni nanoparticles, encapsulating, electrocatalyst
DOI: https://pubs.acs.org/doi/10.1021/acscatal.1c01284
