Insights into CO poisoning in high performance proton-conducting solid oxide fuel cells

Abstract High performance anode supported proton-conducting solid oxide fuel cells (PC-SOFC) were fabricated and their performance in syngas was studied. PC-SOFC button cells produced a maximum power density of 812 mW cm −2 in H 2 at 750 °C. It was found that the CO-containing feed streams could drastically degrade the performance of PC-SOFC. Based on the experimental results and the theoretical analysis, the detailed process of the CO-induced Ni catalyst deactivation was identified. This process could be divided into three distinguishable stages during the continuous exposure of the Ni catalyst in the CO-containing environment. The first stage could be described using the CO surface active site blocking mechanism, which was further confirmed by CO/H 2 competitive adsorption model. The second stage deactivation was proposed to be related to the carbon deposition at TPB (Triple-phase Boundary). The deactivation during this stage was accelerated by the electrochemical conversion of H 2 . The last stage was attributed to the coking of Ni catalyst and the resulted metal dusting effect.