title: Highly selective, facile NO2 reduction to NO at cryogenic temperatures on hydrogen precovered gold.
abstract: We have discovered that NO(2) is reduced to NO at 77 K by hydrogen precovered gold in vacuum. Here, we investigate the partial reduction of NO(2) to NO on an atomic-hydrogen populated model gold catalyst for a more fundamental understanding of the surface chemistry of hydrogenation. Gold-based catalysts have been found to be active for many hydrogenation reactions, but few related fundamental studies have been conducted. Our experimental results reveal a high catalytic activity for gold: indeed, NO(2) is reduced to NO with 100% conversion and 100% selectivity at temperatures lower than 120 K. Density functional theory calculations and reflection-absorption infrared spectroscopy measurements indicate that HNO(2) and N(2)O(3) are intermediates which are highly dependent on surface hydrogen concentrations; subsequent hydrogenation of HNO(2) and dissociation of N(2)O(3) upon annealing induces the production of NO and H(2)O.
authors.affiliation: Department of Chemical Engineering, Center for Nano and Molecular Science and Technology, Texas Materials Institute, Austin, Texas 78712-0231, United States.
authors.forename: Ming
authors.initials: M
authors.lastname: Pan
authors.forename: Hyung Chul
authors.initials: HC
authors.lastname: Ham
authors.forename: Wen-Yueh
authors.initials: WY
authors.lastname: Yu
authors.forename: Gyeong S
authors.initials: GS
authors.lastname: Hwang
authors.forename: C Buddie
authors.initials: CB
authors.lastname: Mullins
mesh_terms: D002384:Catalysis; D006046:Gold / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D009569:Nitric Oxide / Q000138:chemical synthesis* / Q000737:chemistry*; D010084:Oxidation-Reduction; D011789:Quantum Theory; D013696:Temperature
chemical_list: D009569:Nitric Oxide; D006046:Gold; D006859:Hydrogen