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Updated: May 16, 2026

Supercritical Nitrogen Processing for the Purification of Reactive Porous Materials
Published on: May 15, 2015
Highly selective, facile NO2 reduction to NO at cryogenic temperatures on hydrogen precovered gold
Ming Pan1, Hyung Chul Ham, Wen-Yueh Yu
1Department of Chemical Engineering, Center for Nano and Molecular Science and Technology, Texas Materials Institute, Austin, Texas 78712-0231, United States.
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.
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