Modulating surface chemistry of copper oxides through annealing environment for enhanced selective HMF oxidation: A DFT-electrochemical approach

• Published in: Journal of environmental chemical engineering 2024-10, Vol.12 (5), p.113444, Article 113444
• Main Authors: Mumtazah, Nadia, Chan, Chen-Hui, Catherine, Stefani, Pham, Minh-Trang Huynh, Choi, Jinu, Yoo, Jong Suk, Chiang, Chia-Ying
• Format: Article
• Language: English
• Subjects: 2,5-diformylfuran; 5-hydroxymethylfurfural oxidation; Copper oxides; DFT calculation; Electrocatalyst
• ISSN: 2213-3437
• DOI: 10.1016/j.jece.2024.113444

A comprehensive study was reported to address the effects of both copper (I) and copper (II) oxides on the electrocatalytic 5-hydroxymethylfurfural (HMF) oxidation reaction. Cu2O (1 1 1) demonstrated an outstanding selectivity (80 %) and product yield in the oxidation process towards 2,5-diformylfuran (DFF). The recorded current density of 0.12 mA/cm2 for Cu2O-dominated sample was doubled comparing to its counterpart electrocatalyst, CuO, under mild pH 9.6 condition. Periodic density functional theory calculations show that the higher DFF selectivity for the Cu2O dominant catalyst can be explained by the Cu2O (1 1 1) surface being more oxyphilic while being less carbophilic than the CuO (1 1 1) surface. As a result, all the reaction intermediates that lead to DFF are stabilized significantly more than those that lead to other products. This work deepens the understanding of copper-based oxide material for the HMF electrooxidation and provides a new window for designing electrocatalyst. [Display omitted] •Copper (I) and copper (II) oxide dominant electrodes have been successfully synthesized.•Comprehensive study on both copper (I) and (II) oxides catalysts in HMF oxidation.•Cu2O dominant electrode exhibits the highest activity for HMF oxidation.•Reaction pathway of HMF oxidation on CuO (1 1 1) and Cu2O (1 1 1) was proposed by DFT.•Solution environment also affects the product selectivity in HMF electro-oxidation.