Preparation of highly dispersed metallic Pt nanoparticle catalysts for low-temperature propene combustion

Propene (C3H6) combustion is crucial in emission-control applications. A set of Pt/gamma-Al2O3 samples were synthesized through either the chemical reduction-deposition method (denoted as RD) or the incipient wetness impregnation method (denoted as IW) and employed for C3H6 combustion. By adjusting the synthesis conditions, Pt/gamma-Al2O3 catalysts with diverse Pt nanoparticle size distributions were produced. Due to the reduction in particle size, the Pt-RD catalysts exhibited better catalytic activity than the Pt-IW catalysts. With an average Pt nanoparticle size of 2.93 nm, the 1% Pt-RD3 catalyst exhibited optimal catalytic performance, with a complete C3H6 conversion at 110 degrees C. A higher proportion of Pt-0 was confirmed to be beneficial to C3H6 combustion by X-ray photoelectron spectroscopy (XPS) investigations. Moreover, Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) analysis demonstrated that Pt-0 atoms at edge and corner surface sites participated in C3H6 oxidation as active sites. Extended experiments revealed that the 1% Pt-RD3 catalyst exhibited strong tolerance against water and high oxidation reactivities of other pollutants in vehicle emission. This work provides an effective attempt toward synthesis and applications of Pt-based catalysts for hydrocarbons combustion.