Surface Lattice Oxygen Confined Hydrogen Transfer for Electrochemical Acetonitrile Hydrogenation
Hao Zhang, Linghao Yu, Yancai Yao, Biao Zhou, Jundi Cheng, Xupeng Liu, Ziyue Chen, Hao Zhang, Long Zhao, Lizhi Zhang
Abstract
Electrochemical synthesis of ethylamine from acetonitrile with H 2 O is a promising alternative to the traditional H 2 -based process but is challenged by the sluggish hydrogenation process with the inefficient supply of active hydrogen species (H*). Herein, we report an accelerated hydrogen transfer strategy to facilitate on-site electrochemical hydrogenation of acetonitrile for ethylamine synthesis. This strategy was realized by a monolithic electrode composed of oxygen vacancies (OVs)-rich titanium dioxide nanoarrays grown on Ti foam in combination with Ni single atoms (Ni 1 /OVs-TiO 2 NA), which enabled the efficient electrochemical water dissociation into H* along with the optimized electronic structure of surface lattice oxygens by leveraging adjacent OVs, effectively weakening the binding strength of O–H bonds for the subsequent fast transfer of confined H* mediated by surface lattice oxygens. With further incorporation of Ni single atoms as H* trapping centers for the hydrogenation step, the as-prepared Ni 1 /OVs-TiO 2 NA delivered an impressive electrocatalytic performance of acetonitrile hydrogenation with an ethylamine yield rate of 6.93 mmol h –1 mg Ni –1 and a Faraday efficiency of 94%, 8.8-fold higher than that of OVs-free counterpart (0.78 mmol h –1 mg Ni –1, 39%). This work clarifies the promotion effect of surface lattice oxygen on hydrogen-transfer-related electrochemical hydrogenation reactions and offers a water-based ethylamine synthesis strategy.