Modulation of Pt electron transfer via engineered ultra-thin TiO₂-Al₂O₃ interfaces for coke-resistant methane dry reforming.

Abstract

Dry reforming of methane (DRM) is plagued by rapid catalyst deactivation, primarily due to carbon deposition exacerbated by exposed Al₂O₃ surfaces in conventional mixed-phase supports. Herein, we construct a well-defined Pt/TiO₂-Al₂O₃ interface by depositing an ultra-thin anatase TiO₂ overlayer onto Al₂O₃ via an in situ growth strategy to eliminate detrimental Al₂O₃ exposure. Characterization coupled with DFT calculations reveal that the Al₂O₃ support induces lattice contraction and electron enrichment of the ultra-thin TiO₂ layer through interfacial stress and charge transfer. This concurrently activates lattice oxygen (Ti-O) and optimizes Pt charge density, endowing the catalyst with balanced CH₄ activation and a heightened CH* → C* barrier. The resulting Pt/TiO₂-Al₂O₃ catalyst achieves exceptional durability, maintaining 91% CH₄ conversion at 800 °C for 100 h with negligible carbon deposition, outperforming Pt/Al₂O₃ and Pt/TiO₂ benchmarks. This work demonstrates that engineering a continuous ultra-thin TiO₂ overlayer on Al₂O₃ is a superior alternative to mixed-phase supports, providing a generalizable blueprint for coke-resistant catalyst design via precise interface control.