Experimental and mechanistic understanding of photo-oxidation of methanol catalyzed by CuO/TiO2-spindle nanocomposite:Oxygen vacancy engineering  

作　　者：Quanquan Shi Zhaoxian Qin Changlin Yu Ammara Waheed Hui Xu Yong Gao Hadi Abroshan Gao Li 

机构地区：[1]College of Science,Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resource,Inner Mongolia Agricultural University,Hohhot 010018,China [2]School of Chemical Engineering,Key Laboratory of Petrochemical Pollution Process and Control Guangdong Province,Guangdong University of Petrochemical Technology,Maomirtg 525000,China [3]State Key Laboratory of Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China [4]School of Chemistry and Biochemistry,Georgia Institute of Technology,Atlanta,Georgia 30332,USA

出　　处：《Nano Research》2020年第4期939-946,共8页纳米研究（英文版）

基　　金：Q.Q.S.thanks the Postdoctoral Science Foundation of China(No.223232),the Natural Science Foundation of Inner Mongolia Autonomous Region(No.2018BS02004);the major special topics of Inner Mongolia science and technology department(No.20181351);Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(No.NJYT-20-B20);the Program of Higher-level Talents of Inner Mongolia Agricultural University(No.NDYB2016-03);LiaoNing Revitalization Talents Program(No.XLYC1807121);Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2019)for financial support.

摘　　要：We report experimental and mechanistic understanding of methanol oxidation to produce methyl formate using CuO/Ti02-spindle composite as a promising photocatalyst under mild conditions with over 97%conversion and 83%selectivity.The catalysts are obtained via precise depositing of CuO nanoclusters(size:~3.5 nm)at the{101}facet of the TiO2 to optimally tune exciton recombination through oxygen vacancies generation,evidenced by photoluminescence and Raman spectroscopy measurements.The turnover frequency(TOF)and the apparent quantum efficiency(AQE)of the 7%CuO/TiO2-spindle composites reach up to 23.8 molmethanol·gcat^-1·h^-1 and 55.2%at 25℃,respectively,which are substantially higher than these previously reported photocatalysts.Further,the in-situ attenuated total reflection infrared spectroscopy analysis reveals that the methanol oxidation most likely takes place through the conversion of adsorbed methoxy(CH30^*)to formaldehyde(CHO^*)intermediate,a subject of major debate for a long time.The adsorbed formaldehyde(CHO^*)thus produced reacts with another CH30^*species in its close proximity to form the final product of methyl formate.Results of this study provide insights into the reaction mechanism,and offer guidelines to systematically develop and apply photocatalysts for methanol conversion and related reactions via surface engineering.

关 键 词：CuO/Ti02 nanocomposite methyl formate in-situ attenuated total reflection infrared spectroscopy photocatalysis oxygen vacancy METHANOL 

分 类 号：O64[理学—物理化学]