Suppression of Carbon Deposition at CeO[sub 2]-Modified Ni/YSZ Anodes in Weakly Humidified CH[sub 4] at 850°C

Abstract

Carbon deposition at Ni/ yttria-stabilized zirconia (YSZ) anodes with and without CeO 2 modification (with CeO 2 loading of 4.6 wt % in the anode) was investigated in methane with 3% and 10% H 2 O. The electrochemical performance of the Ni/YSZ anode in methane with 3% H 2 O deteriorated sharply under open-circuit voltage (OCV) conditions, and the anode was completely ruined due to the formation of solid carbon at the anode after exposure to methane under OCV for 2 h at 850°C. The addition of the CeO 2 is effective in the suppression of carbon deposition at the Ni/YSZ anode. The CeO 2 -modified Ni/YSZ anode developed in the present study was successfully operated in methane with 10% H 2 O at 850°C for 3 h under OCV condition without carbon deposition or electrochemical performance deterioration. These attractive results are attributed to the novel microstructure of the CeO 2 -modifled Ni/YSZ anode where the Ni and YSZ particles were homogenously covered with a thin layer of CeO 2 with size around 100 nm.