Surface hydroxyl-induced Pt⁰ clusters on TiO₂ for synergistic water gas shift catalysis

The regulation of active site electronic structure is a central strategy for optimizing supported metal catalysts, yet achieving precise and comprehensive control remains challenging due to the complex nature of metal-support interactions. This work presents a practical and reproducible approach to this challenge through the deliberate regulation of surface hydroxyls on TiO₂ via a titanate-derived synthesis and controlled calcination, which correlates with improved water gas shift catalysis activity of Pt/TiO₂ catalyst. The mechanistic interpretation by multiple characterizations suggest that a higher hydroxyl concentration is associated with the formation of more reduced Pt species, which enhanced CO activation. Subsequently, hydroxyl groups can be directly consumed by CO, which shows a correlation with the formation of oxygen vacancies. Catalysts with a higher density of oxygen vacancies exhibit stronger H₂O dissociation capability. This work develops hydroxyl-content control as a viable strategy for catalyst optimization, supported by a mechanistic framework that rationalizes its impact on both metal electronic structure and oxide surface chemistry.