Dual Activation of Molecular Oxygen and Surface Lattice Oxygen in Single Atom Cu1/TiO2 Catalyst for CO Oxidation

The in-depth mechanism on the simultaneous activation of O-2 and surface lattice O2- on one active metallic site has not been elucidated yet. Herein, we report a strategy for the construction of abundant oxygen activation sites by rational design of Cu-1/TiO2 single atom catalysts (SACs). The charge transfer between isolated Cu and TiO2 support generates abundant Cu-I and 2-coordinated O-lat sites in Cu-1-O-Ti hybridization structure, which facilitates the chemisorption and activation of O-2 molecules. Simultaneously, the Cu-1-O-Ti induced TiO2 lattice distortion activate the adjacent surface lattice O2-, achieving the dual activation of O-2 and surface lattice O2-. The Cu-1-O-Ti active site switches the CO oxidation mechanism from Eley-Rideal (80 degrees C) to Mars-van Krevelen route (200 degrees C) with the increase of reaction temperature. The dual activation of O-2 and surface lattice O2- can by modulating the electron properties of SACs can boost the heterogeneous catalytic oxidation activity.

Automated summary

The mechanism of simultaneous activation of O-2 and surface lattice O2- on one active metallic site is still unclear. In this study, we designed Cu-1/TiO2 single atom catalysts (SACs) with abundant oxygen activation sites. Charge transfer between Cu and TiO2 generates Cu-I and 2-coordinated O-lat sites, facilitating the chemisorption and activation of O-2 molecules. The Cu-1-O-Ti active site also induces TiO2 lattice distortion, activating adjacent surface lattice O2-, achieving the dual activation of O-2 and surface lattice O2-. Modulating the electron properties of SACs can boost heterogeneous catalytic oxidation activity.