Engineering and activating adaptive Pt/TiO₂ interfacial perimeters for efficient and robust CO oxidation.

Abstract

Design of active but stable interfaces in supported metal catalysts represents an emerging research theme lately, given its critical importance for tailoring and enabling selectivity and efficiency of heterogeneous reactions. Herein, we report a generic sunlight-driven epitaxial growth strategy to engineer catalytically active interfacial perimeters defined by subnanometric Pt dispersed on TiO₂ nanoparticle supports. Such interfacial perimeters are populated with a unique type of Pt⁴⁺-O-Ti³⁺ reactive sites, resulting in much more efficient and robust CO oxidation than most supported Pt catalysts reported so far. These subnanometric PtO_x-TiO₂ interfacial structures are found to dynamically evolve during CO oxidation, adaptively optimizing their adsorption behaviors toward reactants and SO₂. Combined with the activated interfacial lattice oxygen species via the electronic metal-support interaction effect, the Mars-van Krevelen pathway is activated at low temperature to oxidize CO at high conversion efficiency. The sunlight-driven synthetic strategy is successfully extended to other metal catalysts supported by metal oxide and perovskite materials, offering a new paradigm for designing adaptive catalysts toward a variety of heterogeneous catalytic reactions.