Engineering Low-Coordinated Pt Sites through Supported Polyhedral Nanoparticles for Enhanced Low-Temperature Toluene Catalytic Oxidation

Engineering low-coordinated Pt sites represents a promising strategy to boost catalysis, yet their precise control to optimize structure-activity relationships for volatile organic compounds oxidation remains challenging. Herein, we achieved abundant low-coordinated Pt sites by constructing highly dispersed and well-defined polyhedral Pt nanoparticles on a porous silica support (Pt-APSiO₂) for toluene oxidation. The amino-functionalized silica provides coordination environments for [PtCl₆]^2- precursors that regulate the reduction kinetics to favor polyhedral morphology formation. The resulting Pt-APSiO₂ catalyst showed exceptional performance in toluene oxidation with an extremely low T₉₀ of 148 °C. Structural characterization revealed that the polyhedral Pt nanoparticles possessed a reduced coordination number of 7.38, leading to an upward shift in the d-band center to -1.88 eV. This shifts endowed Pt sites with stronger adsorption and activation for both toluene and O₂. This work demonstrates the feasibility of morphology-directed synthesis for tailoring active site coordination environments, advancing rational design principles for environmental catalysis.