(500a) Non-Oxidative Conversion of Methane into Light Hydrocarbons Using Single-Atom Platinum Catalysts

Nanoceria-supported atomic Pt catalysts (denoted as Pt₁@CeO₂) have been synthesized and demonstrated as advanced catalysts for non-oxidative, direct conversion of methane. These catalysts were synthesized by calcination of Pt-impregnated porous ceria nanoparticles at high temperature (ca. 1,000 ^oC), 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 Pt₁@CeO₂ catalysts exhibited much superior catalytic performance to its nanoparticulated counterpart, achieving 14.4% of methane conversion at 975 ^oC and 74.6% selectivity toward C₂ products (ethane, ethylene and acetylene). Comparative studies of the Pt₁@CeO₂ 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 C₂ hydrocarbons.