Transition metal oxide/hydroxide coatings for (photo)-electrocatalytic biomass valorization

Biomass-derived compounds offer a sustainable alternative to fossil-based feedstocks in the chemical industry. Co-electrolysis of water and biomass-derived organic molecules, such as aldoses, furanic compounds, or alcohols, enables the simultaneous production of high-value platform chemicals at the anode and low-carbon hydrogen at the cathode via the hydrogen evolution reaction. This electrolytic process can operate under mild conditions (temperatures < 40°C, atmospheric pressure) and without noble metals, making it both energy-efficient and cost-effective. Suppressing OER at the anode not only enhances safety by avoiding explosive O₂/H₂ mixtures but also enables the development of membrane-less alkaline electrolyzers, significantly reducing system complexity and costs.Among biomass-derived molecules, 5-hydroxymethylfurfural (HMF), obtained from the acid dehydration of glucose or fructose, stands out as a pivotal platform chemical. Its electrooxidation to 2,5-furandicarboxylic acid (FDCA), a biobased precursor for high-performance polymers like polyamides, polyesters, and polyurethanes, holds immense promise. FDCA can replace petroleum-derived terephthalic acid in polyethylene terephthalate (PET) production, yielding polyethylene furanoate (PEF), a biodegradable polymer with superior barrier and thermal properties due to its furan ring. With the global demand for FDCA rising, developing economically viable and sustainable production methods is critical. The first part of this presentation will highlight our group’s recent advances in the selective electrooxidation of HMF (HMFOR) to FDCA under alkaline conditions, using Ni hydroxide-based electrocatalysts doped with transition metals (Cu and Mn). These innovations aim to expand the HMFOR potential window in membrane-less alkaline electrolyzers, improving efficiency and selectivity.Additionally, we will discuss the selective valorization of glycerol, a low-cost and abundant biosourced byproduct of biodiesel production. Our research focuses on the photoelectrocatalytic oxidation of glycerol in a PEM photoelectrolyzer to co-produce low-carbon H₂ and high-value chemicals such as glyceraldehyde and dihydroxyacetone under mild pH conditions. These compounds serve as key precursors for cosmetics, polymers, and biodegradable emulsifiers. To achieve this, we synthesized a WO₃-coated photoanode to explore the synergy between electro- and photo-catalytic effects in a PEM cell, offering a scalable and sustainable pathway for biomass upgrading.