Asymmetric Pt1O4-Ov Dual Active Sites Induced by NbO x Clusters Promotes CO Synergistical Oxidation

Pt/CeO2 single-atom catalysts are attractive materials for CO oxidation but normally show poor activity below 150 degrees C mainly due to the unicity of the originally symmetric Pt1O4 structure. In this work, a highly active and stable Pt-1/CeO2 single-site catalyst with only 0.1 wt % Pt loading, achieving a satisfied complete conversion of CO at 150 degrees C, can be obtained through fabricating asymmetric Pt1O4-oxygen vacancies (O-v) dual-active sites induced by well-dispersed NbOx clusters. Specifically, the formation of new Ce-O-Nb interactions weakened the strength of the original Pt-O-Ce bond, thus transferring the originally near-perfect square-planar Pt1O4 into the distorted square-planar one, along with forming abundant O-v around the Pt site. Hence, the promoted CO activation on the asymmetric Pt1O4 structure and the facilitated dissociation of the O-2 on the neighboring O-v site synergistically improved the CO catalytic oxidation performance. The fabrication of such asymmetric Pt1O4-O-v double-active sites was also active for the oxidation of other typical hydrocarbons pollutants such as C7H8 and C3H6 from exhaust gases, shedding light on engineering high-efficiency Pt-based oxidation catalysts for low-temperature environmental catalysis.