Authors: Lili Han, Pengfei Ou, Wei Liu, Xiang Wang, Hsiao-Tsu Wang, Rui Zhang, Chih-Wen Pao, Xijun Liu, Way-Faung Pong, Jun Song, Zhongbin Zhuang, Michael V. Mirkin, Jun Luo, Huolin L. Xin
Published: 2022-06-01
Source: Full article
Anion exchange membrane fuel cells are limited by the slow kinetics of alkaline hydrogen oxidation reaction (HOR). Here, we establish HOR catalytic activities of single-atom and diatomic sites as a function of *H and *OH binding energies to screen the optimal active sites for the HOR. As a result, the Ru-Ni diatomic one is identified as the best active center. Guided by the theoretical finding, we subsequently synthesize a catalyst with Ru-Ni diatomic sites supported on N-doped porous carbon, which exhibits excellent catalytic activity, CO tolerance, and stability for alkaline HOR and is also superior to single-site counterparts. In situ scanning electrochemical microscopy study validates the HOR activity resulting from the Ru-Ni diatomic sites. Furthermore, in situ x-ray absorption spectroscopy and computational studies unveil a synergistic interaction between Ru and Ni to promote the molecular H