title: The O, OH and OOH-assisted selective coupling of methanol on Au-Ag(111).
abstract: Using density functional theory (DFT) calculations, we performed a thorough theoretical investigation on the catalytic mechanism of oxidative self-coupling of methanol with molecular oxygen on Au-Ag catalysts. It is found that molecular oxygen can be activated via a hydroperoxyl (OOH) intermediate by taking a hydrogen atom from co-adsorbed methanol with an energy barrier of 0.51 eV, which is actually the rate determining step for the overall reaction. The O, OH and OOH oxidant formation proceeds via two channels of I and II with low barriers. We demonstrated that the oxidative coupling of methanol by OOH, atomic oxygen, and hydroxyl is much more favorable than the total oxidation of methanol, and is responsible for the high selectivity of Au-Ag catalysts in methanol oxidation. The revealed activation mechanism provides an efficient pathway for optimizing the selective coupling of methanol with dioxygen.
authors.affiliation: Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Institute of Applied Physics, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Normal College, Gaoxin Road 115, Guiyang, Guizhou 550018, P. R. China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Zhong
authors.forename: Jinxia
authors.initials: J
authors.lastname: Liang
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
authors.forename: Xinrui
authors.initials: X
authors.lastname: Cao
authors.forename: Chuanyi
authors.initials: C
authors.lastname: Jia
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang