title: Conversion of methane to methanol with a bent mono(μ-oxo)dinickel anchored on the internal surfaces of micropores.
abstract: The oxidation of methane to methanol is a pathway to utilizing this relatively abundant, inexpensive energy resource. Here we report a new catalyst, bent mono(μ-oxo)dinickel anchored on an internal surface of micropores,which is active for direct oxidation. It is synthesized from the direct loading of a nickel precursor to the internal surface of micropores of ZSM5 following activation in O2. Ni 2p3/2 of this bent mono(μ-oxo)dinickel species formed on the internal surface of ZSM5 exhibits a unique photoemission feature, which distinguishes the mono(μ-oxo)dinickel from NiO nanoparticles. The formation of the mono(μ-oxo)dinickel species was confirmed with X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). This mono(μ-oxo)dinickel species is active for the direct oxidation of methane to methanol under the mild condition of a temperature as low as 150 °C in CH4 at 1 bar. In-situ studies using UV-vis, XANES, and EXAFS suggest that this bent mono(μ-oxo)dinickel species is the active site for the direct oxidation of methane to methanol. The energy barrier of this direct oxidation of methane is 83.2 kJ/mol.
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States.
authors.forename: Junjun
authors.initials: J
authors.lastname: Shan
authors.forename: Weixin
authors.initials: W
authors.lastname: Huang
authors.forename: Luan
authors.initials: L
authors.lastname: Nguyen
authors.forename: Ying
authors.initials: Y
authors.lastname: Yu
authors.forename: Shiran
authors.initials: S
authors.lastname: Zhang
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Li
authors.forename: Anatoly I
authors.initials: AI
authors.lastname: Frenkel
authors.forename: Franklin Feng
authors.initials: FF
authors.lastname: Tao