Evaluación del impacto del HCl sobre el ánodo Ni-CeO2 dopado con W en una celda SOFC operada con H2 y biogás

Abstract

Investigation has conducted on the poisoning effect of HCl on theperformance of solid oxide fuel cell (SOFC) with W-Ni-CeO2 as anode fed by H2 or biogas at 750 °C. Experiments were performed under different HCl concentrations (100-1000 ppm) in H2 at 340 mA·cm2 and 250 ppm HCl in biogas (CH4/CO2/H2:70/25/5) at 89 mA·cm2. The cell behavior was evaluated periodically using electrochemical methods. In H2, the HCl concentrations up to 500 ppm hadslightly influence on cell performance. Performance loss is attributed to microstructural changes and Cl adsorption onto Ni and Ce surfaces. In biogas, the presence of 250 ppm HCl provokes important oscillations in the potential under load demand and a performance loss. These results could be caused by theadsorption-desorption processes of Cl on Ni and Ce surfaces diminishing the number of active sites. Also, the presence of CO2 and H2O could promote the oxidation of Ni and CeO2-x reducing their catalytic activity