Dynamic cooperations between lattice oxygen and oxygen vacancies for photocatalytic ethane dehydrogenation by a self-restoring LaVO_(4)catalyst  

作　　者：Fen Wei Weichao Xue Zhiyang Yu Xue Feng Lu Sibo Wang Wei Lin Xinchen Wang 

机构地区：[1]State Key Laboratory of Photocatalysis on Energy and Environment,College of Chemistry,Fuzhou University,Fuzhou 350108,China

出　　处：《Chinese Chemical Letters》2024年第3期171-176,共6页中国化学快报（英文版）

基　　金：financially supported by the National Key R&D Program of China(Nos.2021YFA1502100 and 2022YFE0114800);the National Natural Science Foundation of China(No.21973014)。

摘　　要：Thermocatalytic nonoxidative ethane dehydrogenation(EDH)is a promising strategy for ethene production but suffers from intense energy consumption and poor catalyst durability;exploring technology that permits efficient EDH by solar energy remains a giant challenge.Herein,we present that an oxygen vacancy(O_v)-rich LaVO_(4)(LaVO_(4)-O_v)catalyst is highly active and stable for photocatalytic EDH,through a dynamic lattice oxygen(O_(latt.))and O_(v)co-mediated mechanism.Irradiated by simulated sunlight at mild conditions,LaVO_(4)-O_(v)effectively dehydrogenates undiluted ethane to produce C_(2)H_(4)and CO with a conversion of 2.3%.By loading a small amount of Pt cocatalyst,the evolution and selectivity of C_(2)H_(4)are enhanced to 275μmol h^(-1)g^(-1)and 96.8%.Of note,LaVO_(4)-O_(v)appears nearly no carbon deposition after the reaction.The isotope tracked reactions reveal that the consumed O_(latt.)recuperates by exposing the used catalyst with O_(2),thus establishing a dynamic cycle of O_(latt.)and achieving a facile catalyst regeneration to preserve its intrinsic activity.The refreshed LaVO_(4)-O_(v)exhibits superior reusability and delivers a turnover number of about 305.The O_(v)promotes photo absorption,boosts ethane adsorption/activation,and accelerates charge separation/transfer,thus improving the photocatalytic efficiency.The possible photocatalytic EDH mechanism is proposed,considering the key intermediates predicted by density functional theory(DFT)and monitored by in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS).

关 键 词：PHOTOCATALYSIS Ethane dehydrogenation ETHENE LaVO_(4) Oxygen vacancy 

分 类 号：TQ221.211[化学工程—有机化工] O643.36[理学—物理化学] O644.1[理学—化学]