Asymmetric Pt<sub>1</sub>O<sub>4</sub>–O<sub>v</sub> Dual Active Sites Induced by NbO<sub><i>x</i></sub> Clusters Promotes CO Synergistical Oxidation
Junjie Wen, Jianjun Chen, Rongbing Nie, Zhiyu Li, Weihao Zhang, Jinyan Cao, Pengfei Xie, Qiulin Zhang, Ping Ning, Jiming Hao
Abstract
Pt/CeO 2 single-atom catalysts are attractive materials for CO oxidation but normally show poor activity below 150 °C mainly due to the unicity of the originally symmetric Pt 1 O 4 structure. In this work, a highly active and stable Pt 1 /CeO 2 single-site catalyst with only 0.1 wt % Pt loading, achieving a satisfied complete conversion of CO at 150 °C, can be obtained through fabricating asymmetric Pt 1 O 4 -oxygen vacancies (O v ) dual-active sites induced by well-dispersed NbO x 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 Pt 1 O 4 into the distorted square-planar one, along with forming abundant O v around the Pt site. Hence, the promoted CO activation on the asymmetric Pt 1 O 4 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 Pt 1 O 4 –O v double-active sites was also active for the oxidation of other typical hydrocarbons pollutants such as C 7 H 8 and C 3 H 6 from exhaust gases, shedding light on engineering high-efficiency Pt-based oxidation catalysts for low-temperature environmental catalysis.