Catalyst Chemical State during CO Oxidation Reaction on Cu(111) Studied with Ambient-Pressure X-ray Photoelectron Spectroscopy and Near Edge X-ray Adsorption Fine Structure Spectroscopy
- 25 August 2015
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 137 (34), 11186-11190
- https://doi.org/10.1021/jacs.5b07451
Abstract
The chemical structure of a Cu(111) model catalyst during the CO oxidation reaction in the CO+O2 pressure range of 10-300 mTorr at 298-413 K was studied in situ using surface sensitive X-ray photoelectron and adsorption spectroscopy techniques [X-ray photoelectron spectroscopy (XPS) and near edge X-ray adsorption fine structure spectroscopy (NEXAFS)]. For O2:CO partial pressure ratios below 1:3, the surface is covered by chemisorbed O and by a thin (∼1 nm) Cu2O layer, which covers completely the surface for ratios above 1:3 between 333 and 413 K. The Cu2O film increases in thickness and exceeds the escape depth (∼3-4 nm) of the XPS and NEXAFS photoelectrons used for analysis at 413 K. No CuO formation was detected under the reaction conditions used in this work. The main reaction intermediate was found to be CO2(δ-), with a coverage that correlates with the amount of Cu2O, suggesting that this phase is the most active for CO oxidation.Keywords
Funding Information
- Basic Energy Sciences (DE-AC02-05CH11231)
This publication has 30 references indexed in Scilit:
- The effect of step geometry in copper oxidation by hyperthermal O2 molecular beam: Cu(511) vs Cu(410)The Journal of Chemical Physics, 2012
- Methodology for the structural characterisation of Vx Oy species supported on silica under reaction conditions by means of in situ O K‐edge X‐ray absorption spectroscopyPhysica Status Solidi (b), 2009
- Catalytic oxidation of CO on CuOx revisited: Impact of the surface state on the apparent kinetic parametersCatalysis Today, 2009
- Surface Chemistry of Cu in the Presence of CO2 and H2OLangmuir, 2008
- Ambient pressure photoelectron spectroscopy: A new tool for surface science and nanotechnologySurface Science Reports, 2008
- Methanol Oxidation on a Copper Catalyst Investigated Using in Situ X-ray Photoelectron SpectroscopyThe Journal of Physical Chemistry B, 2004
- Copper (sub)oxide formation: a surface sensitive characterization of model catalystsPhysical Chemistry Chemical Physics, 2000
- Methanol Synthesis and Reverse Water–Gas Shift Kinetics over Cu(110) Model Catalysts: Structural SensitivityJournal of Catalysis, 1996
- Carbon Monoxide Oxidation over Three Different Oxidation States of Copper: Metallic Copper, Copper (I) Oxide, and Copper (II) Oxide - A Surface Science and Kinetic StudyJournal of Catalysis, 1994
- Calculations of electron inelastic mean free paths. V. Data for 14 organic compounds over the 50–2000 eV rangeSurface and Interface Analysis, 1994