Evaluation of the Effect of Sulfur on the Performance of Nickel/Gadolinium-Doped Ceria Based Solid Oxide Fuel Cell Anodes.

ABSTRACT: The focus of this study is the measurement and understanding of the sulfur poisoning phenomena of Ni/gadolinium-doped ceria (CGO) based solid oxide fuel cells (SOFC). Cells with Ni/CGO10 and NiCu5/CGO40 anodes were characterized by using impedance spectroscopy at different temperatures and H₂ /H₂ O fuel ratios. The short-term sulfur poisoning behavior was investigated systematically at temperatures of 800-950?°C, current densities of 0-0.75?A?cm^-2 , and H₂ S concentrations of 1-20?ppm. A sulfur poisoning mitigation effect was observed at high current loads and temperatures. The poisoning behavior was reversible for short exposure times. It was observed that the sulfur-affected processes exhibited significantly different relaxation times that depend on the Gd content in the CGO phase. Moreover, it was demonstrated that the capacitance of Ni/CGO10 anodes is strongly dependent on the temperature and gas-phase composition, which reflects a changing Ce³⁺ /Ce⁴⁺ ratio.

SUBMITTER: Riegraf M 

PROVIDER: S-EPMC5324695 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature