Nanoceria-Supported Single-Atom Platinum Catalysts for Direct Methane Conversion

Nanoceria-supported atomic Pt catalysts (denoted as Pt 1 @CeO 2 ) have been synthesized and demonstrated with advanced catalytic performance for the nonoxidative, direct conversion of methane. These catalysts were synthesized by calcination of Pt-impregnated porous ceria nanoparticles at high temperature (ca. 1000 °C), with the atomic dispersion of Pt characterized by combining aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analyses. The Pt 1 @CeO 2 catalysts exhibited much superior catalytic performance to its nanoparticulated counterpart, achieving 14.4% of methane conversion at 975 °C and 74.6% selectivity toward C 2 products (ethane, ethylene, and acetylene). Comparative studies of the Pt 1 @CeO 2 catalysts with different loadings as well as the nanoparticulated counterpart reveal the single-atom Pt to be the active sites for selective conversion of methane into C 2 hydrocarbons.