报告题目：Identification of Catalytically Active Sites in Carbon-based Catalysts for Electrochemical CO2 Reduction
Designing effective electrocatalysts for the carbon dioxide (CO2) reduction reaction (CRR) is an appealing approach to tackling the challenge posed by rising CO2 levels and realizing a closed carbon cycle. However, CO2electrocatalysis still lacks a fundamental understanding owing to the complicated CRR mechanism and lack of model study systems. Herein, we have designed a model single-nickel-atom catalyst with a uniform structure and well-defined Ni-N4moiety on a conductive carbon support to explore the electrochemical CRR. Based on operando X-ray absorption near-edge structure spectroscopy, Raman spectroscopy and near atmospheric X-ray photoelectron spectroscopy investigations, Ni+ in the single-nickel-atom catalyst resulting from in situ Ni2+ reduction was found to be highly active for CO2 activation, acting as an authentic catalytically active site for the CRR. Furthermore, through combination with a kinetics study, the rate-determining step of the CRR was determined to be *CO2- + H+ → *COOH. This study tackles the four challenges faced by the CRR, namely, activity, selectivity, stability, and dynamics.
Bin Liu received his B.Eng. (1st Class Honors) and M.Eng. degrees in Chemical Engineering from the National University of Singapore, and obtained his Ph.D. degree in Chemical Engineering from University of Minnesota in 2011. Thereafter, he moved to University of California, Berkeley and worked as a postdoctoral researcher in Department of Chemistry during 2011–2012 before joining School of Chemical and Biomedical Engineering at Nanyang Technological University as an Assistant Professor in 2012. He is now an Associate Professor at NTU. His main research interests are electrocatalysis, photovoltaics and photoelectrochemistry. He has published more than 150 SCI papers with 15000 total citations and the h-index is 50. More information can be found at http://www.ntu.edu.sg/home/liubin/home.html.