Application of hydrogen-storage alloy electrode in electrochemical reduction of glucose

Electrolysis of glucose was performed at constant potential using hydrogen-storage alloy as catalytic reduction electrode. A superficial treatment and activation of the hydrogen-storage alloy powder had an obvious effect on improving the current efficiency for the generation of sorbitol. The most favorable results were obtained when a current density of 8 mA cm−2, a voltage of 4.0–5.0 V and a pH of 8 at a temperature of 30 °C are used. Prior to use the electrode was treated for 2 h at 80 °C with a solution containing KBH4 (0.5 mol/l), KF (0.5 mol/l) and KOH (6 mol/l). Under optimized conditions the current efficiency for sorbitol by electrolyzing glucose exceeded 90%. The yield of sorbitol was around 80%. The lifetime of the electrode was tested and analyzed, and methods of regeneration are discussed.