Chlorine contaminants poisoning of solid oxide fuel cells

Abstract

Investigation has been conducted on the poisoning effect of various contaminants containing chlorine at ppm level (<10 ppm) on the performance of Ni-YSZ anode-supported solid oxide fuel cells. The results indicate that cell performance drops by exposure to 1 ppm Cl2(g) at 750 °C, whereas the introduction of Cl2(g) with concentration higher than 5 ppm causes only a slight degradation at 850 °C. The presence of 2–6 ppm CH3Cl(g) and C2H3Cl(g) can also induce measurable cell performance decline at 750 and 850 °C and this deterioration cannot be completely removed after switching to pure fuel at 850 °C. No performance loss is found when the cell is operated in fuel containing 1–8 ppm HCl(g) at 750 and 850 °C. It is thus concluded that chlorine in the form of Cl2(g) yields the largest poisoning effect at 750 °C, while the degradation rate caused by addition of C2H3Cl(g) increases with the increase of operation temperature. Agglomerations at anodic region are observed in the samples after poisoning test by Cl2(g), CH3Cl(g), and C2H3Cl(g), but the anode microstructure is uniform for the sample exposed to HCl(g) for poisoning test.