Effect exerted by partial pressures of hydrogen on the faradaic efficiency, in the electrochemical reduction of carbon dioxide. Part A

The hydrogen discharge is a competitive reaction in the electrochemical reduction of carbon dioxide in aqueous or acidic media. Thus in order to try to inhibit it. In this paper, we report the influence of partial pressures CO2/H-2 on the electrochemical reduction of carbon dioxide based on the principle of Le Chatelier. The voltamefric studies at atmospheric pressure indicate that the arrangement of the electrodes is of utmost importance when gaseous products are obtained, as they block the surface leading a loss of the effective area of the elecfrode. Moreover, voltamefric studies in the presence and absence of carbon dioxide suggest the radical anion surface formation at -1.8 V vs. Ag/AgCl KCl sat. Voltamefric and electrolysis studies at high pressure for sulphate buffer systems [H2SO4/K2SO4 pH=2], showed that the glassy carbon elecfrode in the sulphate buffer under 20 atm. of carbon dioxide and at -1.8 V, generated HCOOH as the only product of carbon dioxide electroreduction with a faradaic efficiency of 1.8%. Finally, it was found that the various hydrogen partial pressures applied did not exert a significant effect on the faradaic efficiency on the HCOOH production, or the charge consumed in the process.