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.