Structure Sensitivity of Au‐TiO2 Strong Metal–Support Interactions

Abstract Strong metal–support interactions (SMSI) is an important concept in heterogeneous catalysis. Herein, we demonstrate that the Au‐TiO 2 SMSI of Au/TiO 2 catalysts sensitively depends on both Au nanoparticle (NP) sizes and TiO 2 facets. Au NPs of ca. 5 nm are more facile undergo Au‐TiO 2 SMSI than those of ca. 2 nm, while TiO 2 {001} and {100} facets are more facile than TiO 2 {101} facets. The resulting capsulating TiO 2− x overlayers on Au NPs exhibit an average oxidation state between +3 and +4 and a Au‐to‐TiO 2− x charge transfer, which, combined with calculations, determines the Ti:O ratio as ca. 6:11. Both TiO 2− x overlayers and TiO 2− x ‐Au interface exhibit easier lattice oxygen activation and higher intrinsic activity in catalyzing low‐temperature CO oxidation than the starting Au‐TiO 2 interface. These results advance fundamental understanding of SMSI and demonstrate engineering of metal NP size and oxide facet as an effective strategy to tune the SMSI for efficient catalysis.