Engineering Multi-Site Platinum Ensembles Synergistically Boosts Catalysis.

Engineering stable and efficient noble metal ensembles with multi-type active sites while understanding the role of each site at the atomic level remains a significant challenge in heterogeneous catalysis. Herein, a sub-nanometric Pt ensemble catalyst with a diverse array of active sites is constructed via a dual-confinement strategy, which exhibits superior activity and durability with minimal Pt loading (0.13 wt.%). Simultaneously, the roles of different Pt sites at the atomic scale are determined through in situ characterization methods and density functional theory (DFT) calculations. Specifically, Pt top sites predominantly serve as pivotal centers for O═O bond activation, whereas Pt-O-Si interfacial sites primarily govern the activation of H─OH and C─H bonds. The reactive oxygen species (O2 -, O2 2-, and -OH) generated from O2 and H2O activation synergistically enhance formaldehyde (HCHO) oxidation and shorten the reaction pathway. This study sheds light on a better understanding and rational design of catalyst active sites via precise synthesis of multi-site ensembles or discerning the distinct contributions of various catalytic sites.