Electrocatalytic Refinery of Biomass-Based 5-Hydroxymethylfurfural to Fine Chemicals

Because of depleting fossil-fuel reserves, together withthe impactsof climate change, alternative eco-friendly production of high-valuechemicals and renewables is needed. Biomass feedstock is of particularresearch interest. 5-Hydroxymethylfural (HMF) is a versatile precursorthat can be converted to high-value chemicals via electrolysis. Reductiongenerates precursors for ethers, ketones, polyurethanes, polyesters,and polyethers, e.g., 2,5-dihydroxymethylfuran (DHMF) and 2,5-dimethyletrahydrofuran(DHMTHF), together with high-energy-density premium biofuels, e.g.,2,5-dimethylfuran (DMF), 2,5-hexanedione (HD) and 5,5 & PRIME;-bis(hydroxymethyl)hydrofuroin (BHH). Oxidation HMF yields valuable chemical products,including 2,5-diformyl furan (DFF), 5-hydroxymethyl-2-furan carboxylicacid (HMFCA), 2,5-furan dicarboxylic acid (FDCA), and maleic acid(MA) that are precursors/intermediates for the polymer industry andchemical/pharmaceutical production(s). In this review, we 1) reporta comparative summary of the electrocatalytic refinery of HMF, bothelectro-oxidation and electroreduction pathways, 2) appraise advancesin HMF electroreduction reaction (HRR) and HMF electro-oxidation reaction(HOR), 3) assess reaction pathways and mechanisms, 4) establish adesign for electrocatalysts including selection of metal materials,design of the geometric structure, and electronic structural modificationsto boost HRR and HOR activity and selectivity, 5) evaluate the impactof reaction parameters including pH, electrolyte composition, appliedpotential, and initial substrate concentration on HRR and HOR, and6) provide a prospect on future electrochemical refinement of HMF.We conclude that an improved understanding of reaction conditionsis needed to practically boost selectivity and activity for the electrochemicalrefinement of HMF. Findings will benefit in design for electrochemistryand eco-friendly chemistry in generating fine chemicals and, therefore,are of interest to researchers and manufacturers.

Automated summary

Due to the depletion of fossil fuel reserves and the impact of climate change, there is a need for alternative eco-friendly production of high-value chemicals and renewables. This review focuses on the electrocatalytic refinery of 5-Hydroxymethylfural (HMF), a versatile precursor that can be converted to valuable chemical products via electrolysis. The review discusses the electroreduction and electro-oxidation pathways of HMF, advances in HMF electroreduction reaction (HRR) and HMF electro-oxidation reaction (HOR), design of electrocatalysts, reaction pathways and mechanisms, and the impact of reaction parameters. The findings have implications for the design of eco-friendly chemistry and fine chemical production.