Electron penetration triggering interface activity of Pt-graphene for CO oxidation at room temperature.

Wang, Yong; Ren, Pengju; Hu, Jingting; Tu, Yunchuan; Gong, Zhongmiao; Cui, Yi; Zheng, Yanping; Chen, Mingshu et al. · Nat Commun · 2021

basic_science · Level V

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Abstract

Achieving CO oxidation at room temperature is significant for gas purification but still challenging nowadays. Pt promoted by 3d transition metals (TMs) is a promising candidate for this reaction, but TMs are prone to be deeply oxidized in an oxygen-rich atmosphere, leading to low activity. Herein we report a unique structure design of graphene-isolated Pt from CoNi nanoparticles (PtǀCoNi) for efficiently catalytic CO oxidation in an oxygen-rich atmosphere. CoNi alloy is protected by ultrathin graphene shell from oxidation and therefore modulates the electronic property of Pt-graphene interface via electron penetration effect. This catalyst can achieve near 100% CO conversion at room temperature, while there are limited conversions over Pt/C and Pt/CoNiO<sub>x</sub> catalysts. Experiments and theoretical calculations indicate that CO will saturate Pt sites, but O<sub>2</sub> can adsorb at the Pt-graphene interface without competing with CO, which facilitate the O<sub>2</sub> activation and the subsequent surface reaction. This graphene-isolated system is distinct from the classical metal-metal oxide interface for catalysis, and it provides a new thought for the design of heterogeneous catalysts.