Efficient integration of carbon dioxide reduction and 5-hydroxymethylfurfural oxidation at high current density

Abstract

Commercialization of the electrochemical CO₂ reduction reaction (CO₂RR) is a crucial step towards carbon utilization and addressing climate change. However, its low energy efficiency in full electrolytic systems poses significant challenges. To overcome this, we investigate an integrated electrolytic cell coupling the CO₂RR with the 5-hydroxymethylfurfural oxidation reaction (HMFOR), a promising alternative to the oxygen evolution reaction (OER) at the anode. The utilization of nickel-phosphorus (NiP) electrocatalysts achieves high faradaic efficiency (90%) and stability (>200 redox cycles) for the anodic HMFOR to produce 2,5-furandicarboxylic acid (FDCA) at a high current density of 100 mA cm⁻². Simultaneously, Sn, Ag and Cu nanoparticles act as efficient cathode electrocatalysts in a flow cell reactor, to produce formate, syngas, C₂₊ hydrocarbon and other CO₂RR products. Compared to the OER-CO₂RR, the integrated HMFOR-CO₂RR system demonstrates an energy efficiency increase of more than 10%. Additionally, economic analysis shows a 45% reduction in the levelized cost of potassium formate production in an optimistic scenario. This integrated CO₂RR-HMFOR electrocatalytic system holds promise for commercializing CO₂ reactors.