A-site-deficiency facilitated in situ growth of bimetallic Ni-Fe nano-alloys: a novel coking-tolerant fuel cell anode catalyst.

To date, most investigations of Ni-Fe bimetallic catalysts for solid oxide fuel cells (SOFCs) have focused on materials with micro-scale particle sizes, which severely restrict their catalytic activity. In this study, we fabricated a Ni- and/or Fe-doped A-site-deficient LaSrCrO3 perovskite (A-LSC) bimetallic anode material on which the in situ exsolution of uniformly dispersed nano Ni, Fe and Ni-Fe alloy with an average particle size of 25 to 30 nm was facilitated by the introduction of A-site deficiency under a reducing atmosphere. The dopants were shown to significantly enhance the electrical conductivity of the material by many orders of magnitude. Further characterization of the bimetallic material showed that the addition of Fe changed the reduction behavior and increased the amount of oxygen vacancies in the material. Fuel cell performance tests demonstrated that the prepared bimetallic anode catalyst with a highly catalytically active nano Ni-Fe alloy promoted the electrochemical performance in 5000 ppm H2S-syngas and improved the carbon deposition resistance compared to a monometallic anode catalyst.