Pt-stabilized electron-rich Ir structures for low temperature methane combustion with enhanced sulfur-resistance

Abstract

Improving the sulfur-resistance of low-temperature methane combustion catalysts is great important for industrial applications. Electronic engineering of catalyst active sites is effective in tuning the catalytic performance. Herein, IrPt0.5/TiO2 catalysts with electron-rich Ir structures modulated by Pt exhibit excellent low temperature sulfur-resistance towards methane combustion. The integrated characterization coupled with density functional theory calculations reveal that the strong electronic interaction between Ir and Pt induces the formation of electron-rich Ir structures. The electron-rich Ir structures with more defective oxygen vacancy and better redox ability greatly boost the adsorption and activation of O2 while suppress SO2 adsorption on the catalyst surface, leading to excellent sulfur tolerance towards methane combustion. This work highlights a practical electronic engineering strategy to tune the electron structure of Ir active sites for the development of practical methane oxidation catalysts.