The Restructuring-Induced CoO x Catalyst for Electrochemical Water Splitting

作者：Maoyu Wang, Qingbo Wa, Xiaowan Bai, Zuyun He, Widitha S. Samarakoon, Qing Ma, Yingge Du, Yan Chen, Hua Zhou, Yuanyue Liu, Xinwei Wang, Zhenxing Feng · 发表于：JACS Au · 年份：2021 · DOI：10.1021/jacsau.1c00346 · 被引用次数：79 · 研究领域：Electrocatalysts for Energy Conversion、Advanced Photocatalysis Techniques、Copper-based nanomaterials and applications

High Resolution Image Download MS PowerPoint Slide Restructuring is an important yet less understood phenomenon in the catalysis community. Recent studies have shown that a group of transition metal sulfide catalysts can completely or partially restructure during electrochemical reactions which then exhibit high activity even better than the best commercial standards. However, such restructuring processes and the final structures of the new catalysts are elusive, mainly due to the difficulty from the reaction-induced changes that cannot be captured by ex situ characterizations. To establish the true structure–property relationship in these in situ generated catalysts, we use multimodel operando characterizations including Raman spectroscopy, X-ray absorption spectroscopy, and X-ray reflectivity to investigate the restructuring of a representative catalyst, Co 9 S 8, that shows better activity compared to the commercial standard RuO 2 during the oxygen evolution reaction (OER), a key half reaction in water-splitting for hydrogen generation. We find that Co 9 S 8 ultimately converts to oxide cluster (CoO x ) containing six oxygen coordinated Co octahedra as the basic unit which is the true catalytic center to promote high OER activity. The density functional theory calculations verify the in situ generated CoO x consisting of edge-sharing CoO 6 octahedral clusters as the actual active sites. Our results also provide insights to design other transition-metal-based materials as e...