USTC groups of Professor Yao Tao and Professor Wei Shiqiang from National Synchrotron Radiation Laboratory (NSRL) developed an operando synchrotron radiation XAFS technology combined with theoretical calculations to accurately identify the real structure and dynamic evolution of active sites of cobalt-based catalysts during the electrocatalytic hydrogen evolution reaction. The research is published in Natural Catalysis (Nature Catalysis 2, 134 (2019)). They unraveled that the electrocatalyst underwent structural reconstruction into a high-valence “HO–Co₁–N₂” moiety by the binding between initial isolated “Co₁–N₄” sites with electrolyte hydroxide. Furthermore, water molecular adsorbed to the active center to the form “H₂O-(HO-Co₁-N₂)” reaction intermediates driven by the applied overpotential. The corresponding theoretical calculations confirm the configurations of these key intermediates and further reveal the mechanism of the reaction. The research finds that the performance and stability of this obtained cobalt-based electrocatalyst are close to commercial Pt/C electrocatalyst, but the cost is less than half of that of Pt/C, showing a board application prospect.

Fig. The Schematic diagram of operando synchrotron radiation revealing real active sites for electrocatalysts

Article

Linlin Cao, Qiquan Luo, Wei Liu, Yue Lin, Xiaokang Liu, Yuanjie Cao, Wei Zhang,Yuen Wu, Jinlong Yang, Tao Yao* and Shiqiang Wei. Identification of single-atom active sites in carbon-based cobalt catalysts during electrocatalytic hydrogen evolution. Nature Catalysis 2, 134 (2019).