Pt Atomic Single-Layer Catalyst Embedded in Defect-Enriched Ceria for Efficient CO Oxidation

The local coordination structure of metal sites essentially determines the performance of supported metal catalysts. Using a surface defect enrichment strategy, we successfully fabricated Pt atomic single-layer (Pt_ASL) structures with 100% metal dispersion and precisely controlled local coordination environment (embedded vs adsorbed) derived from Pt single-atoms (Pt₁) on ceria-alumina supports. The local coordination environment of Pt₁ not only governs its catalytic activity but also determines the Pt₁ structure evolution upon reduction activation. For CO oxidation, the highest turnover frequency can be achieved on the embedded Pt_ASL in the CeO₂ lattice, which is 3.5 times of that on the adsorbed Pt_ASL on the CeO₂ surface and 10-70 times of that on Pt₁. The favorable CO adsorption on embedded Pt_ASL and improved activation/reactivity of lattice oxygen within CeO₂ effectively facilitate the CO oxidation. This work provides new insights for the precise control of the local coordination structure of active metal sites for achieving 100% atomic utilization efficiency and optimal intrinsic catalytic activity for targeted reactions simultaneously.