An ingenious Ni/Ce co-doped titanate based perovskite as a coking-tolerant anode material for direct hydrocarbon solid oxide fuel cells

Abstract

For decades, Ni based cermet anodes for solid oxide fuel cells (SOFCs) have been suffering from poisoning from sulfur in fuel and carbon deposition while operating on hydrocarbon fuel. Using perovskite as an alternative can effectively alleviate these problems. However, its performance is unsatisfying. In this work, a lanthanum strontium titanate based perovskite oxide with facile modification of Ni and Ce (LSCNT) was fabricated by a modified sol–gel method. The exsolution of Ni surrounded by uniformly dispersed Ce species in the perovskite lattice could only be obtained by sintering the material in consecutive atmospheres of air and 10% H₂/Ar. The solid oxide fuel cell (SOFC) equipped with an LSCNT anode exhibited desirable electrochemical performance and stability with 5000 pm H₂S/H₂ and dry methane fuel. The presence of exsolved metallic Ni provided strong active sites for the fuel oxidation reaction and simultaneously the Ce species with a redox couple provided Ni with abundant oxygen ions. The synergetic effect between Ce and Ni facilitates the electrochemical reaction and promotes the removal of carbon deposition. All these features make LSCNT a promising sulfur and carbon-deposition tolerant anode material for SOFCs.