Direct and TEMPO‐Mediated Electro‐Oxidation of 5‐(Hydroxymethyl)furfural in Organic and Hydro‐Organic Media

• Published in: ChemElectroChem Vol. 11; no. 12
• Main Authors: Vo, Nhat Tam, Cacciuttolo, Quentin, Pasquier, David, Larmier, Kim
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 17.06.2024; Weinheim : Wiley-VCH; Wiley-VCH
• Subjects: 5-Hydroxymethylfurfural; Acetonitrile; Aldehydes; Biomass; Buffer solutions; Carboxylic acids; Chemical Physics; Electrocatalysis; Fluorescence; Formic acid; Furfural; Hydroxymethylfurfural; Oxidation; Physics; Piperidine; Room temperature; Substrates; TEMPO; Electrocatalysis; TEMPO; Biomass; 5-Hydroxymethylfurfural
• ISSN: 2196-0216; 2196-0216
• DOI: 10.1002/celc.202400116

Biomass‐derived 5‐hydroxymethyl furfural (5‐HMF) is a promising starting substrate for producing two high value‐added products 2,5‐diformylfuran (DFF) and 2,5‐furandicarboxylic acid (FDCA). DFF, which is produced by selectively oxidizing the hydroxymethyl group of 5‐HMF to an aldehyde group, has many applications in pharmaceuticals, macrocyclic ligands and fluorescent materials. Oxidizing both aldehyde and hydroxymethyl groups of 5‐HMF leads to FDCA, which is an important monomer in the production of a bioplastic polyethylene furanoate polymer. Electrochemical conversion of 5‐HMF is a potential route for sustainable chemical production of DFF and FDCA. In fact, using 2,2,6,6‐tetramethyl‐ piperidine‐1‐oxyl (TEMPO) as a redox mediator leads to a highly efficient and selective electro‐oxidation of 5‐HMF into FDCA in a basic buffer solution. In this report, the direct and TEMPO‐mediated electro‐oxidation of 5‐HMF was investigated in various organic and hydro‐organic media at room temperature. Direct electro‐oxidation leads to a low selective conversion of 5‐HMF to DFF (10 % of yield) and the formation of unwanted products such as formic acid and protoanemonin (90 % and 37 % of yield respectively) in acetonitrile. Electrocatalytic 5‐HMF conversion in the presence of TEMPO as a redox mediator achieved a near‐quantitative yield of DFF in acetonitrile and γ‐valerolactone. Importantly, we demonstrate the role of water in the conversion of aldehydes to carboxylic acids. Electrooxidation of biomass‐derived 5‐Hydroxymethyl furfural (5‐HMF) to produce 2,5‐diformylfuran (DFF), either direct and 2,2,6,6‐tetramethyl‐ piperidine‐1‐oxyl (TEMPO)‐mediated, is investigated in various organic and hydro‐organic media at room temperature. The direct electrooxidation mainly yields unwanted products such as formic acid and protoanemonin, near‐quantitative yields of DFF are obtained in acetonitrile and γ‐valerolactone.