Electrochemical coupling of benzene hydrogenation and water electrolysis

To establish an efficient process for hydrogenation of benzene to cyclohexane as one of the candidates for transportable, chemical hydrogen carriers, a combined scheme of water electrolysis and hydrogenation in the polymer electrolyte cell was proposed. A Rh-Pt electrode, which was found to be more active for electrochemical hydrogenation of benzene, was formed on a polymer electrolyte (Nafion, Du Pont) by means of soaking-reduction. Using an electrochemical cell, hydrogen pumping rate, electrochemical hydrogenation of benzene and water electrolysis were investigated at temperatures 25-70 degrees C and atmospheric pressure, followed by combined electrochemical hydrogenation of benzene and: water electrolysis. It became clear that benzene could be electrochemically hydrogenated on the cathode with hydrogen (proton), which was produced by water electrolysis at the anode and then pumped. The combined effects were recognized as a drop in decomposition voltage of water as well as a rise in current. (C) 2000 Elsevier Science B.V. All rights reserved.