Constructing dual active sites for synergistic electrocatalysis of hydrogen oxidation: single-metal-atoms anchored on WCO MXene

• Published in: Materials chemistry frontiers Vol. 6; no. 17; pp. 2458 - 2467
• Main Authors: Zhao, Lianming, Han, Xiaonan, Tong, Yanfu, Ding, Yanping, Kong, Weichao, Wang, Jiajun, Li, Bingyu, Xu, Jing, Bai, Peng, Wei, Xing
• Format: Journal Article
• Published: 22.08.2022
• ISSN: 2052-1537
• DOI: 10.1039/d2qm00440b

The promising alkaline exchange membrane fuel cells (AEMFCs) are subject to the sluggish kinetics of anodic hydrogen oxidation reaction (HOR). Balancing the adsorption/desorption ability toward H* and OH* is considered to be an efficient way to improve the HOR efficiency, but is extremely hard on one active site. Here, single metal atoms (M sa ) anchored on W 2 CO 2 MXene (W 2 CO 2 -M sa ) were built, including a series of 3d, 4d, and 5d metals. First-principles calculations indicate that the charge transfer between M sa and W 2 CO 2 induces an efficient dual-active site, i.e. , M sa as the OH* active site and its adjacent O atoms as the H* active site. The dual active sites on W 2 CO 2 -M sa can not only avoid the competitive adsorption of H* and OH* but also display a synergistic catalytic effect towards the HOR. Remarkably, W 2 CO 2 -M sa (M sa = Mn, Fe, Co, Ir, and Pt) shows both high stability and superior HOR activity over bulk Pt, suggesting their huge potential as anodic electrocatalysts for AEMFCs. The W 2 CO 2 MXene-supported single-atom catalysts (W 2 CO 2 -M sa , M sa = Mn, Fe, Co, Ir, and Pt) show super performance towards the hydrogen oxidation reaction in alkaline media.