Tuning Adsorbate-Mediated Strong Metal-Support Interaction by Oxygen Vacancy: A Case Study in Ru/TiO2

Angew Chem Int Ed Engl. 2024 May 14:e202407025. doi: 10.1002/anie.202407025. Online ahead of print.

Abstract

The adsorbate-mediated strong metal-support interaction (A-SMSI) offers a reversible means of altering the selectivity of supported metal catalysts, thereby providing a powerful tool for facile modulation of catalytic performance. However, the fundamental understanding of A-SMSI remains inadequate and methods for tuning A-SMSI are still in their nascent stages, impeding its stabilization under reaction conditions. Here, we report that the initial concentration of oxygen vacancy in oxide supports plays a key role in tuning the A-SMSI between Ru nanoparticles and defected titania (TiO2-x). Based on this new understanding, we demonstrate the in-situ formation of A-SMSI under reaction conditions, obviating the typically required CO2-rich pretreatment. The as-formed A-SMSI layer exhibits remarkable stability at various temperatures, enabling excellent activity, selectivity and long-term stability in catalyzing the reverse water gas-shift reaction. This study deepens the understanding of the A-SMSI and the ability to stabilize A-SMSI under reaction conditions represents a key step for practical catalytic applications.

Keywords: CO2 hydrogenation; SMSI; adsorbate mediation; heterogeneous catalysis; oxygen vacancy.