Selective electrosynthesis of platform chemicals from the electrocatalytic reforming of biomass-derived hexanediol

6-Hydroxyhexanoic acid and adipic acid are platform chemicals and are widely used as building blocks for the synthesis of important polymers. Nevertheless, the industrial syntheses of these two chemicals are fossil fuel-based and involve the use of corrosive acid and emission of the NOx greenhouse gas. In this study, the electrosynthesis of 6-hydroxyhexanoic acid and adipic acid from the electrochemical oxidation of hexanediol at the nanoporous nickel oxyhydroxide modified electrode was explored as an environmentally-benign alternative to the industrial syntheses of 6-hydroxyhexanoic acid and adipic acid. The effects of electrolysis conditions, including the electrolyte pH and applied potentials, on faradaic efficiency and product distribution of the electrochemical oxidation of hexanediol, were thoroughly examined through a series of controlled-potential electrolyses. In addition, the scale-up electrosynthesis of 6-hydroxyhexanoic acid and adipic acid using a flow-type electrolyzer was also demonstrated.