文献类型：期刊文献

中文题名：Insight into the photoexcitation effect on the catalytic activation of H_(2) and C-H bonds on TiO_(2)(110)surface

作者：Min Zhou[1];Hai-Feng Wang[1]

机构：[1]Key Laboratory for Advanced Materials,Centre for Computational Chemistry and Research Institute of Industrial Catalysis,East China University of Science and Technology,Shanghai 200237,China

年份：2022

卷号：33

期号：10

起止页码：4705

中文期刊名：Chinese Chemical Letters

外文期刊名：中国化学快报（英文版）

收录：CSTPCD;;Scopus;CSCD:【CSCD2021_2022】；PubMed;

基金：supported by National Nature Science Foundation of China(Nos.21873028.91945302);National Ten Thousand Talent Program for Young Top-notch Talents in China,Shanghai Shu-Guang project(No.17SG30);the Fundamental Research Fundsfor the Central Universities.

语种：英文

中文关键词：Density functional theory calculation;Photocatalysis;H_(2)activation;C-H bond activation;TiO_(2)

摘要：Semiconductor photocatalysis holds great promise for breaking the inert chemical bonds under mild condition;however,the photoexcitation-induced modulation mechanism has not been well understood at the atomic level.Herein,by performing the DFT+U calculations,we quantitatively compare H_(2) activation on rutile TiO_(2)(110)under thermo-versus photo-catalytic condition.It is found that H2 dissociation prefers to occur via the heterolytic cleavage mode in thermocatalysis,but changes to the homolytic cleavage mode and gets evidently promoted in the presence of photoexcited hole(h^(+)).The origin can be ascribed to the generation of highly oxidative lattice O-radical(O_(br)^(·?))with a localized unoccupied O-2p state.More importantly,we identify that this photo-induced promotion effect can be practicable to another kind of important chemical bond,i.e.,C-H bond in light hydrocarbons including alkane,alkene and aromatics;an exception is the C(sp^(1))-H in alkyne(HC≡CH),which encounters inhibition effect from photoexcitation.By quantitative analysis,the origins behind these results are attributed to the interplay between two factors:C-H bond energy(E_(bond))and the acidity.Owing to the relatively high E_(bond) and acidity,it favors the C(sp^(1))-H bond to proceed with the heterolytic cleavage mode in both thermo-and photo-catalysis,and the photoexcited O_(br)^(·?)is adverse to receiving the transferred proton.By contrast,for the other hydrocarbons with moderate/low E_(bond),the O_(br)^(·?)would enable to change their activation mode to a more favored homolytic one and evidently decrease the C-H activation barrier.This work may provide a general picture for understanding the photocatalytic R-H(R=H,C)bond activation over the semiconductor catalyst.