Korean Journal of Chemical Engineering | 2021
Characteristics of Sr0.92Y0.08Ti1−xNixO3−δ anode for direct internal steam methane reforming in solid oxide fuel cells
Abstract
Sr0.92Y0.08Ti1−xNixO3−δ (SYTN) having a perovskite structure was investigated as a direct internal steam methane reforming catalyst for use in solid oxide fuel cells. To analyze the effect of Ni-ion doping, 0, 3, and 5 mol% of Ni is doped at the B-site of Sr0.92Y0.08TiO3−δ (SYT). On doping, each Ni2+ cation substitutes a Ti4+ cation in SYT to form an oxygen vacancy with two electron holes, thus acting as an oxygen-ion conductor. The number of oxygen vacancies increases with increase in Ni-ion doping. In particular, Sr0.92Y0.08Ti0.95Ni0.05O3−δ (SYTN5) shows excellent catalytic activity for steam methane reforming, yielding CH4 conversions of 0.80, 0.96, and 0.99 at 700, 800, and 900 °C, respectively, and H2-to-CO ratios of 3.38, 3.32 and 3.24 at 700, 800, and 900 °C, respectively, which are very close to the theoretical values for the steam methane reforming and water gas shift reactions. The excellent electrochemical property and high oxygen-ion conductivity of the SYTN5 anode result in good cell performance.