DFT Study of Synergistic Catalysis of the Water‐Gas‐Shift Reaction on Cu–Au Bimetallic Surfaces. Issue 6 (25th February 2016)

• Record Type: Journal Article
• Authors: Saqlain, Muhammad Adnan; Hussain, Akhtar; Siddiq, Dr Muhammad; Leenaerts, Ortwin; Leitão, Alexandre A.
• Is Part Of: ChemCatChem. Volume 8:Issue 6(2016)
• Page Start: 1208
• Page End: 1217
• Publication Date: 2016-02-25
• Subjects: bimetallic surfaces -- DFT -- kinetics -- thermodynamics -- water-gas-shift reaction; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.201501312
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: The water‐gas‐shift reaction (WGSR) is an important industrial process that can be significantly enhanced at suitable catalyst surfaces. In this work, we investigate the catalytic behavior of metallic Cu(1 0 0) and bimetallic Cu–Au(1 0 0) surfaces. With density functional theory calculations, the variation in the Gibbs free energy (Δ G °), the activation barriers, and the rate constants for the WGSR are calculated. The variation in Δ G ° for water dissociation shows that the process is spontaneous up to 520 K on the bimetallic surface and up to 229 K on the Cu(1 0 0) surface. The calculated rate constants for the process also show that the bimetallic surface is much more reactive than the Cu(1 0 0) surface. The calculated pressure–temperature phase diagram for water dissociation shows that the partial pressure of H2 O required for water dissociation on the bimetallic surface is substantially lower than that on the Cu(1 0 0) surface at all the studied temperatures. Additionally, the calculations demonstrate that the kinetics of the water‐gas‐shift reaction is dominated by redox processes on both the surfaces. Abstract : Surface behavior : The catalytic behavior of metallic Cu(1 0 0) and bimetallic Cu–Au(1 0 0) surfaces has been investigated with density functional theory calculations. The variation in the Gibbs free energy (Δ G °), the activation barriers, and the rate constants for the water‐gas‐shift reaction (WGSR) are calculated. The variation in Δ G ° for water dissociation shows that the process is spontaneous up to 520 K on the bimetallic surface and up to 229 K on the Cu(1 0 0) surface.