title: Thermal methane conversion to formaldehyde promoted by single platinum atoms in PtAl2O4 (-) cluster anions.
abstract: Identification and mechanistic study of thermal methane conversion mediated by gas-phase species is important for finding potentially useful routes for direct methane transformation under mild conditions. Negatively charged oxide species are usually inert with methane. This work reports an unexpected result that the bi-metallic oxide cluster anions PtAl2 O4 (-) can transform methane into a stable organic compound, formaldehyde, with high selectivity. The clusters are prepared by laser ablation and reacted with CH4 in an ion trap reactor. The reaction is characterized by mass spectrometry and density functional theory calculations. It is found that platinum rather than oxygen activates CH4 at the beginning of the reaction. The Al2 O4 (-) moiety serves as the support of Pt atom and plays important roles in the late stage of the reaction. A new mechanism for selective methane conversion is provided and new insights into the surface chemistry of single Pt atoms may be obtained from this study.
authors.affiliation: Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (P.R. China).
authors.forename: Yan-Xia
authors.initials: YX
authors.lastname: Zhao
authors.forename: Zi-Yu
authors.initials: ZY
authors.lastname: Li
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yuan
authors.forename: Xiao-Na
authors.initials: XN
authors.lastname: Li
authors.forename: Sheng-Gui
authors.initials: SG
authors.lastname: He
keywords: cluster anions; density functional computations; mass spectrometry; methane; platinum