TiO_(2)-supported Single-atom Catalysts:Synthesis,Structure,and Application

In recent years,single-atom catalysts(SACs)have attracted increasing attention in catalysis.However,their stability is considerably challenging.As a result,fine-tuning the interaction of metal single atoms(SA)with different types of supports has emerged as an effective strategy for improving their thermal and chemical stabilities.Owing to its non-toxicity,cost-effectiveness,high abundance,and excellent stability,as well as presence of rich,tunable,and reliable anchor sites for metal SA,TiO_(2)has been extensively explored as a superior support for SACs.In this review,recent advances of TiO_(2)-supported SACs(M1/TiO_(2))are discussed,and synthetic strategies,structure elucidation,and catalytic applications are summarized.First,the recently developed synthetic strategies for M1/TiO_(2)arehighlighted and summarized,identifying the major challenges for the precise fabrication of M1/TiO_(2).Subsequently,key characterization techniques for the structure identification of M1/TiO_(2)are discussed.Next,catalytic applications of M1/TiO_(2)are highlighted,viz.photocatalysis,electrocatalysis,and thermocatalysis.In addition,the mechanism via geometric structures and electronic states of metal centers facilitate catalytic reactions is outlined.Finally,opportunities and challenges of M1/TiO_(2)in catalysis are discussed,which may inspire the future development of M1/TiO_(2)for multifunctional catalytic applications.