In‐situ Electrochemical Transformed Cu Oxide from Cu Sulfide for Efficient Upgrading of Biomass Derived 5‐Hydroxymethylfurfural in Anion Exchange Membrane Electrolyzer

• Published in: ChemSusChem 2022-12, Vol.15 (23), p.e202201625-n/a
• Main Authors: Zhao, Heng‐Fan, Yue, Yu‐Ting, Fan, Yi‐Lin, Wang, Ji‐Xiang, Li, Wen‐Hui, Wei, Feng, Liu, Min, Yu, Yan‐Hua, Lu, Wang‐Ting, Zhang, Geng
• Format: Article
• Language: English
• Subjects: 2,5-furandicarboxylic acid; 5-hydroxymethylfurfural; Anion exchanging; Biomass; Copper; Copper converters; electrolysis; heterogeneous catalysis; Hydrogen production; Hydroxymethylfurfural; Membranes; Metal foams; Oxidation
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.202201625

The electrochemical transformation of biomass to high value‐added products is attractive. Herein, Cu sulfide‐mediated in‐situ synthesis of Cu oxide was achieved for efficient electro‐oxidation of biomass derived 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA). The copper foam‐supported Cu sulfide (Cu−S/CF) was in‐situ converted to Cu oxide during the electro‐oxidation process. The in‐situ formed Cu oxide presented high HMF conversion, FDCA yield, and faradaic efficiency in 1 m KOH with HMF concentration up to 100 mm. The oxidation of HMF on Cu oxide started with the formation of high‐valence Cu species with the assistance of OH−, which then oxidized HMF spontaneously. An anion exchange membrane (AEM) electrolyzer with Cu−S/CF as the anode was assembled to continuously produce FDCA with H2 generation at the cathode. The AEM electrolyzer ran stably for 60 h with FDCA content higher than 85 % at a cell voltage between 1.50 and 1.60 V. Biomass electrochemical oxidation: Copper foam‐supported Cu sulfide (Cu−S/CF) is in‐situ converted to Cu oxide during electrochemical oxidation of 5‐hydroxymethylfurfural. The anion exchange membrane electrolyzer with Cu−S/CF as the anode can work stably for at least 60 h, and the 2,5‐furandicarboxylic acid content in the product can be higher than 90 %.