CO₂Conversion to FuelsDriven by Renewable Energy

报告人：Professor Junwang (John) Tang

报告时间：2020年12月15日（星期二）晚上19:00-20:00

报告方式：腾讯会议APP，选择“加入会议”；会议号：841329197,密码:1215

报告人简介：

Professor Junwang (John) Tang（唐军旺教授）is a Fellow of European Academy of Sciences, Fellow of the Royal Society of Chemistry, Director of the University Materials Hub (2016-2019) and Chair of Materials Chemistry and Engineering in the Department of Chemical Engineering at University College London. He received his PhD in Physical Chemistry in DICP in Dalian in 2001 and then took a position at NIMS, Japan as a JSPS fellow. In 2015, he joined the Department of Chemistry at Imperial College London as a senior researcher and then in 2009 he moved to UCL to take a permanent position of Lectureship, followed a promotion to Senior Lecturer, Reader and Full Professor.

Prof. Tang’s current research interest lies in heterogeneous catalysis, encompassing photocatalysis (e.g. activation of small molecules: CH4, C6H6, H2O, N2 and CO2) and microwave catalysis (plastic chemical recycling), together with microwave intensified flow chemical processes. Such studies are undertaken in parallel with the mechanistic understanding by time-resolved spectroscopies to address the renewable energy supply and environmental purification, resulting to >160 papers published in Nature Catalysis, Nature Energy, Chemical Reviews, Chem. Soc. Rev. Materials Today, Nature Commun., JACS, Angew Chemie with >14000 citations (https://scholar.google.com/citations?user=S0jdSPEAAAAJ&hl=en). He has also received many awards, the latest of which are the 2019 IChemE Global Business Start-Up Award and the Runner-up of the IChemE Global Oil and Gas Awards 2019. He also sits on the editorial/advisory board of several international journals, eg. the Editor of Applied Catalysis B and Editor-in-Chief of Journal of Advanced Chemical Engineering, Associate Editor of Chin. J. Catal. And Associate Editor of Asia-Pacific Journal of Chemical Engineering.

报告摘要：

Photocatalytic conversion of carbon dioxide not only provides a renewable energy source, but also potentially mitigates climate change. However, as one of the most stable inorganic molecules, CO₂requires a large amount of energy to be activated, and thus its conversion is an energy-intensive process. To avoid additional CO₂emission from conventional chemical approaches, a promising solution is to use renewable and clean (carbon-zero) energy source to drive the chemical reaction of CO₂reduction. Photocatalytic CO₂conversion by solar energy is such a process that is also a clean and sustainable process for carbon recycle. Since the preliminary demonstration of CO₂conversion to chemicals via photocatalysis in 1970’s, considerable effort has been devoted to develop efficient photocatalyst.

This lecture will start with a brief analysis of CO₂conversion to valuable chemicals in an economical manner. Then the fundamental issues related to charge dynamics in photocatalysis will be discussed. Following it, a feasibility study is presented for CO₂conversion to CO. based on knowledge derived from both the fundamental study and feasibility research, a hybrid material was fabricated, which is composed of a polymer photocatalyst C3N4 (CN) and carbon dots (^mCD) synthesised by a novel microwave method. Such heterostructure composite was used to directly reduce CO₂by H₂O into methanol driven by visible photocatalysis. It has been found that the^mCD possesses unique hole-accepting nature, prolonging the electron lifetime (t₅₀) of CN by four folds compared to the electron-accepting carbon dots fabricated by conventional methods (^sCD), favouring a six-electron product. Furthermore,^mCD-decorated CN stably produces stoichiometric oxygen and methanol with nearly 100% selectivity from water and CO₂, resulting into a quantum efficiency of 2.5% in visible region. Such activity was further confirmed by isotopic labelling, which is more than 100 times higher than the widely reported^sCD-loaded CN which generates a two-electron product CO under the identical conditions. Furthermore the produced methanol has a weak adsorption on the^mCD, which dramatically mitigates its over-oxidation. Such mechanism was also proved by theoretical modelling.