Understanding the intrinsic synergistic mechanism between Pt-O-Ti interface sites and TiO_(2) surface sites of Pt/TiO_(2) catalysts in Fenton-like reaction

摘要

Identifying the active site of oxide-supported metal catalysts and revealing the intrinsic synergistic mechanism between metal and oxide support remain a large challenge.Herein,we report the identification and separation of the Pt-O-Ti interface and TiO_(2) surface in Pt-TiO_(2)-based catalysts by depositing different thickness of TiO_(2) shell with∼0.4-nm micropores onto the surface of Pt/TiO_(2) catalyst through atomic layer deposition(ALD).In the oxidation of 3,3′,5,5′-tetramethylbenzidine(TMB)by hydrogen peroxide(H_(2)O_(2))process,the TiO_(2) microporous shells can prevent the contact between TMB and embedded Pt clusters,but not delay the diffusion of H_(2)O_(2).The heterolysis of H_(2)O_(2) to ·OH occurs on the Pt-O-Ti interface,and the generated•OH migrates to the TiO_(2) surface to supplement the surface lattice oxygen,which sequentially oxidizes TMB to oxTMB.And the synergistic effect between Pt-O-Ti interface active sties and TiO_(2) surface active sites can significantly improve the catalytic performance.Our study provides a guide for the understanding of the intrinsic synergistic mechanism between the metal and oxide support in the metal-oxide catalysts.