报告人：郭正晓, 香港大学, 教授，欧洲科学院外籍院士

主持人（邀请人）：崔小强 教授

报告时间：2024年9月24日（星期二）下午4:00-5:00

报告地点：437ccm必赢国际前卫南区唐敖庆楼D区429

主办单位：汽车材料教育部重点实验室，437ccm必赢国际

报告摘要：

Catalysis is involved in most chemical or energy conversation processes.  Active site is critically important for the effectiveness, efficiency and/or selectivity of a catalyst, where mechanistic understanding holds a key to designing and populating such sites. Noble metals, transition metals (TMs) and their compounds, carbon / graphene -based and other low-dimensional structures offer great scope to catalyse chemical / electrochemical /photochemical energy conversion and storage processes.  Specific functionalities can be effectively tuned by means of atomic doping, defect control, inter-layer spacing, porosity architecting and hybridisation with other nanostructures. The focus here is to demonstrate how those approaches can be effectively engineered to tailor the electrochemical catalysis for oxygen reduction and/or evolution reactions (ORR or OER), which underpins the costs and stability of rechargeable metal–air batteries and regenerative fuel cells – the energy conversion / storage technologies for portable devices, electric vehicles and the smart grid, as well as renewable hydrogen generation. Currently, the commercial noble metal catalysts, such as Pt/C and IrO2/C, only exhibit mono-functional activity for either ORR or OER. Non-noble metal or metal-free materials are increasingly considered as cost-effective alternatives, but their catalytic activities, especially OER performance, are yet to match their metallic counterparts. The alignment of the TM d-band and O p-band is important in tuning the multi-electron transfer pathways and kinetics in transition-metal (TM) oxide catalysts, whereas intra-molecular charge transfer from/to active sites is critical to enable effective catalytic properties in metal-free (e.g. doped carbon/graphene) catalysts. Our systematic development firstly demonstrates the enrichment of N-doping and the graphene / graphitic carbon-nitride intercalation are effectively for enabling rapid four-electron transfer process in ORR, and then switching of ORR and OER by single heat treatment of a metal-organic-framework. By closely coupling theory and experiment, we show the most effective catalytic sites in phosphorus-nitrogen co-doped graphene frameworks (PNGF), and then engineered the synthetic formulations to enrich such sites. The developed electrocatalysts show highly efficient bifunctionality for both ORR and OER, after successive structural optimisation and purposeful enrichment of the active sites. The fundamental insight, design strategy and synthesis approach offer great scope for further development of highly cost-effective energy conversion devices, such as electrolysers, supercapacitors and metal-air batteries.

报告人简介：

Brief Bio-: ZXG is a joint-faculty Chair Professor of Chemistry and Mechanical Engineering and the Executive Director of HKU-ZIRI, the University of Hong Kong, an Honorary Professor of University College London (UCL), a Member of Academia Europaea and a Fellow of Royal Society of Chemistry and of the Institute of Minerals, Metals and Materials. He was a Professor of Chemistry, a theme-leader in energy materials and a Pro-Provost at UCL, and a Lecturer / Professor at Queen Mary, University of London, a research fellow at the University of Oxford and of Strathclyde, respectively, with a PhD from the University of Manchester. Prof. Guo’s group focuses on integrated theoretical and experimental approaches for the design and development of highly functional atomic clusters, nanostructures and materials, as well as their synthesis processes. He has (co-)authored over 300 publications, e.g. in Nature Energy, Nature Comm., Energy Environmental Science, Advanced (Energy, Functional) Materials, Angew Chemie Int. and Physical Review Letters etc.. He is listed as one of the top 1% worldwide highly cited researchers in the past 10 years (ESI) by Clarivate Analytics, and received the Beilby Medal and Prize for “Working theory for industry” jointly from the Society for Chemical Industry, The Royal Society of Chemistry and the Institute of Minerals, Metals and Materials.