Prof. John Wang
Department of Materials Science and Engineering
National University of SingaporeTitle: Heterogeneous Electrocatalysts for Energy and Environment: Single Atoms, Married Atoms or a Few of Atoms in Group, Which One?
Abstract
For both energy and environmental applications, there has been an intensive search for better advanced heterogeneous electrocatalysts of high activity, conversion efficiency, long-term durability and selectivity for a wide variety of chemical reactions. With the steady down-sizing from nanoparticles, clusters and now to single atoms, and the gradual switching from high-cost noble metals to cheap transition metals, there are changes in the bond and coordination environment for each and every atoms involved. These single atoms are not “singles” anymore, and they are actually chemically bonded to the supporting surfaces with various coordination environments, and their catalytic performance is largely controlled by the “marriage” with the substrate surfaces, instead by themselves. On the other hand, for those electrocatalytic reactions involving multiple electron transfers, multiple reaction steps and multiple pathways, single atom catalysts (SACs) have their limitations. There is need to develop strong synergies between single atom and single atom (metal dimers/trimers, which are defined as “married atoms”), and between single atoms with other active centers, including those sub-nano clusters and nanoparticles. In this talk, I will present our latest progress in search for better heterogeneous electrocatalysts, by focusing on the synergies between different active species, with case studies for oxygen reduction reaction (ORR), nitrogen reduction reaction (NRR) and CO2 reduction reaction (CO2RR). For these new heterogeneous electrocatalysts, various in-situ and operando characterizations down to atomic scales, together with computational studies, are important, on top of the conventional experimental studies of catalysts engineering and characterization.
BiographyProfessor John Wang is a Principal Investigator in the Department of Materials Sciences and Engineering (MSE) in National University of Singapore (NUS). His research group, Advanced Ceramics Laboratory, focuses on energy materials and devices, 2D materials chemistry, and nanostructured materials for energy and water technologies. Prof. Wang obtained his Ph.D. (Ceramics) from the University of Leeds, UK, in 1987 and has over 30 years of teaching and research experiences in functional materials and materials chemistry. He served the Head of Department of Materials Science and Engineering at NUS for seven years (July 2013- June 2019). Prof. Wang was elected as an Academician of Asia Pacific Academy of Materials in 2019. In 2020, Prof. Wang was awarded as a highly cited Researcher (Cross-field) by the Clarivate Analytics. As of 1st October 2021, Prof. Wang has over 500 publications with more than 25000 citations and a h-index of 86.