Partial oxidation of methane to methanol by isolated Pt catalyst supported on a CeO2 nanoparticle
So-Hwang Kye, Hee Sun Park, Renqin Zhang, Hee Jung Yang, Kyu Hyoung Lee, Hoyoung Suh, Jin-Gyu Kim, Min Gyu Kim, Gyeong S. Hwang, Nam Hwi Hur
Abstract
Catalytic transformation of methane (CH4) into methanol in a single step is a challenging issue for the utilization of CH4. We present a direct method for converting CH4 into methanol with high selectivity over a Pt/CeO2 catalyst which contains ionic Pt2+ species supported on a CeO2 nanoparticle. The Pt/CeO2 catalyst reproducibly yielded 6.27 mmol/g of Pt with a selectivity of over 95% at 300 °C when CH4 and CO are used as reactants, while the catalyst had a lower activity when using only CH4 without CO. Active lattice oxygen created on the Pt and CeO2 interface provides selective reaction pathways for the conversion of CH4 to methanol. Based on high-angle annular dark-field scanning transmission electron microscopy, x-ray photoelectron spectroscopy, x-ray absorption near-edge structure, extended x-ray absorption fine structure, catalytic studies, and density functional theory calculations, we propose a mechanistic pathway involving CH4 activation at the active site in the vicinity of Pt2+ species.