Competitive C–C and C–H bond scission in the ethanol oxidation reaction on Cu(100) and the effect of an alkaline environment. Issue 23 (5th June 2017)

• Record Type: Journal Article
• Authors: Wu, Zhipeng; Zhang, Minhua; Jiang, Haoxi; Zhong, Chuan-Jian; Chen, Yifei; Wang, Lichang
• Is Part Of: Physical chemistry chemical physics. Volume 19:Issue 23(2017)
• Page Start: 15444
• Page End: 15453
• Publication Date: 2017-06-05
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c7cp01445g
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : C–C bond scission in EOR on Cu(100) will occur in CH2 CO but acetic acid formation will preside under alkaline conditions. Abstract : Direct ethanol fuel cell technology is impeded by inefficient, yet expensive anode catalysts. As such, research on effective and cheap anode catalysts towards complete ethanol oxidation reaction (EOR) is greatly needed. Herein, we report the investigations of the competitive C–C and C–H bond scissions in the EOR involving CH3 CO, CH2 CO, and CHCO species on Cu(100) using density functional theory and transition state theory calculations. The easiest C–C bond cleavage was found in CH2 CO while the most difficult C–H bond cleavage was also found in CH2 CO, both with an activation energy of 1.02 eV. The feasible C–C bond scission may take place in CH2 CO with a rate constant ratio of the C–C to the C–H bond scission at 100 °C of 0.32. Furthermore, in an alkaline environment, the C–H bond scission activation barrier is considerably lowered but the C–C bond cleavage activation barrier is slightly increased for both CH3 CO and CH2 CO species. The reaction of CH3 CO species on Cu(100) under alkaline conditions produces mainly acetic acid with a barrier of 0.49 eV and a rate constant of 4.93 × 10 5 s −1 at 100 °C.