Cobalt Single‐Atom Reverse Hydrogen Spillover for Efficient Electrochemical Water Dissociation and Dechlorination
Qian Zheng, Hengyue Xu, Yancai Yao, Jie Dai, Jiaxian Wang, Wei Hou, Long Zhao, Xingyue Zou, Guangming Zhan, Ruizhao Wang, Kaiyuan Wang, Lizhi Zhang
Abstract
Abstract Efficient water dissociation to atomic hydrogen (H*) with restrained recombination of H* is crucial for improving the H* utilization for electrochemical dechlorination, but is currently limited by the lack of feasible electrodes. Herein, we developed a monolithic single‐atom electrode with Co single atoms anchored on the inherent oxide layer of titanium foam (Co 1 −TiO x /Ti), which can efficiently dissociate water into H* and simultaneously inhibit the recombination of H*, by taking advantage of the single‐atom reverse hydrogen spillover effect. Experimental and theoretical calculations demonstrated that H* could be rapidly generated on the oxide layer of titanium foam, and then overflowed to the adjacent Co single atom for the reductive dechlorination. Using chloramphenicol as a proof‐of‐concept verification, the resulting Co 1 −TiO x /Ti monolithic electrode exhibited an unprecedented performance with almost 100 % dechlorination at −1.0 V, far superior to that of traditional indirect reduction‐driven commercial Pd/C (52 %) and direct reduction‐driven Co 1 −N−C (44 %). Moreover, its dechlorination rate constant of 1.64 h −1 was 4.3 and 8.6 times more active than those of Pd/C (0.38 h −1 ) and Co 1 −N−C (0.19 h −1 ), respectively. Our research sheds light on the rational design of hydrogen spillover‐related electrocatalysts to simultaneously improve the H* generation, transfer, and utilization for environmental and energy applications.