RESUMEN
This study shows the results, for the first time, of an glycerol alkaline-acid electrolyzer. Such a configuration allows spontaneous operation, producing energy and hydrogen simultaneously as a result of the utilization of the neutralization and fuel chemical energy. The electroreformer-built with a 20 wt% Pd/C anode and cathode, and a Na+-pretreated Nafion® 117-can simultaneously produce hydrogen and electricity in the low current density region, whereas it operates in electrolysis mode at high current densities. In the spontaneous region, the maximum power densities range from 1.23 mW cm-2 at 30 °C to 11.9 mW cm-2 at 90 °C, with a concomitant H2 flux ranging from 0.0545 STP m-3 m-2 h-1 at 30 °C to 0.201 STP m-3 m-2 h-1 at 90 °C, due to the beneficial effect of the temperature on the performance. Furthermore, over a chronoamperometric test, the electroreformer shows a stable performance over 12 h. As a challenge, proton crossover from the cathode to the anode through the cation exchange Nafion® partially reduces the pH gradient, responsible for the extra electromotive force, thus requiring a less permeable membrane.
RESUMEN
This study assessed the influence of hydrodynamic conditions on the degradation process of 1-butyl-3-methylimidazolium chloride (BMImCl) solution on a boron-doped diamond anode in a filter-type electrochemical reactor configuration. The results show that this parameter did not significantly affect this process when operating in the laminar regime. However, in the transition regime (Reâ¯≥â¯2000), higher flow rates resulted in a faster removal of BMImCl and total organic carbon, making the process more efficient. Following BMImCl degradation, nitrates were generated at the cathode, then reduced at the cathode to ammonium; combination with free chloride produced at the anode led to the transformation of chloride into combined chlorine forms instead of more toxic oxianions such as chlorate and perchlorate. Thus, the flow rate can be a key parameter for defining operating conditions in which the target BMImCl is more effectively degraded with reduced generation of undesirable secondary products.
