2,5-Bis(hydroxymethyl)furan: A new alternative to HMF for simultaneously electrocatalytic production of FDCA and H2 over CoOOH/Ni electrodes

Simultaneous production of value-added 2,5-furandicarboxylic acid (FDCA) and H 2 from the integrated 5-hydroxymethylfurfural (HMF) oxidation and hydrogen evolution reaction by electrocatalysis has drawn tremendous attention due to the significantly improved energy efficiency. However, HMF is not thermally and chemically stable enough to often cause heavy degradation, impeding its storage and industrialization. In this work, a more stable furan molecule, 2,5-bis(hydroxymethyl)furan (BHMF), was employed as the reaction substrate into the coupling system for the first time. By means of facile electrodeposition and subsequent oxidative activation, the standing CoOOH nanosheet electrocatalyst was fabricated to realize a complete BHMF conversion with 90.2 % FDCA yield and 100 % current efficiency for H 2 evolution. The reaction path and apparent activation energies were therefore discussed. Scalable properties and electrochemical durability of CoOOH were evaluated in a continuous flow reactor to harvest gram-level solid FDCA, highlighting the prospect of green coupling electrolysis for industrial application.