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

摘要

Improving the sulfur-resistance of low-temperature methane combustion catalysts is great important for indus-trial 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 O-2 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.

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