1. NiRu–Mo2Ti2C3O2 as an efficient catalyst for alkaline hydrogen evolution reactions: the role of bimetallic site interactions in promoting Volmer-step kinetics.
- Author
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Xi, Qing, Xie, Fangxia, Sun, Zijun, Liu, Jianxin, Zhang, Xiaochao, Wang, Yawen, Zhou, Aijuan, Ma, Xiaoli, Gao, Xiaoming, Yue, Xiuping, Ren, Jun, Fan, Caimei, Jian, Xuan, and Li, Rui
- Abstract
The Volmer step in alkaline hydrogen evolution reactions (HERs), which supplies H* to the following steps by cleaving H–O–H bonds, is considered the rate-determining step of the overall reaction. The Volmer step involves water dissociation and adsorbed hydroxyl (*OH) desorption; Ru-based catalysts display a compelling water dissociation process in an alkaline HER. Unfortunately, the strong affinity of Ru for *OH blocks the active sites, resulting in unsatisfactory performance during HER processes. Hence, this study investigates a series of key descriptors (ΔG
*H , ΔG2 O*H–OH , ΔG*H , and ΔG*OH ) of TM (Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, or Pt)–Ru/Mo2 Ti2 C3 O2 to systematically explore the effects of bimetallic site interactions on the kinetics of the Volmer step. The results indicate that bimetallic catalysts effectively reduced the strong adsorption of *OH on Ru sites; especially, the NiRu diatomic state shows the highest electron-donating ability, which promoted the smooth migration of *OH from Ru sites to Ni sites. Therefore, Ru, Ni and MXenes are suitable to serve as water adsorption and dissociation sites, *OH desorption sites, and H2 release sites, respectively. Ultimately, NiRu/Mo2 Ti2 C3 O2 promotes Volmer kinetics and has the potential to improve alkaline HERs. This work provides theoretical support for the construction of synergistic MXene-based diatomic catalysts and their wide application in the field of alkaline HERs. [ABSTRACT FROM AUTHOR]- Published
- 2024
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