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

Yong Wang,Liang Yu,Zhongmiao Gong,Fan Yang,Dehui Deng,Wujun Zhang,Chao Ma,Yi Cui,Mingshu Chen,Yunchuan Tu,Yanping Zheng,Jingting Hu,Ye Wang,Xinhe Bao,Pengju Ren

doi:10.1038/s41467-021-26089-y

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/CoNiOx catalysts. Experiments and theoretical calculations indicate that CO will saturate Pt sites, but O2 can adsorb at the Pt-graphene interface without competing with CO, which facilitate the O2 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.

Highlights

Achieving CO oxidation at room temperature is significant for gas purification but still challenging nowadays
We design a unique graphene-isolated Pt from CoNi nanoparticles (PtǀCoNi) catalyst, of which CoNi can be protected by graphene from oxidation in an oxygen-rich atmosphere and effectively trigger the interface activity of Pt–graphene for CO oxidation at room temperature
Pt NPs were synthesized in the form of sol and deposited on them and two control samples, commercial carbon nanotube (CNT) and carbon black (CB), with the same Pt loading amount of 4 wt%

Summary

Introduction

Achieving CO oxidation at room temperature is significant for gas purification but still challenging nowadays. An in situ hydrogen reduction was performed to reduce the surface CoNiOx back to the metallic state (Supplementary Fig. 10), but once exposed to the reaction atmosphere (CO + O2) Co and Ni can be rapidly oxidized even at near room temperature.

Results

Conclusion