Tuning surface chemistry of inverse catalysts ZnOxHy/Pt(111) without site blocking

Abstract

In this study, we explore how the formation of self-assembled porous hydroxylated phases provides a strategy to modulate surface chemistry while preserving the number of active sites. Specifically, we investigated graphene-like ZnO films and related Zn₆O₅H₅ overlayers on Pt(111) as model inverse catalysts with relevance to industrial catalysis. By combining surface science experiments and density functional theory (DFT) calculations, we demonstrate that the formation of ZnO films minimally affects the adsorption properties of CO, a common probe adsorbate for industrially relevant reactions, while significantly blocking surface Pt sites. By contrast, the porous Zn₆O₅H₅ films on Pt not only modulate CO adsorption energies and site preferences, mediated by charge donation and chemical effects facilitated by hydrogen bonding, but also retain a substantial number of vacant Pt sites. These results highlight the potential of self-assembled porous phases as a promising avenue for engineering oxide films on metal catalysts.