Electrochemical and In Situ Spectroscopic Evidences toward Empowering Ruthenium-Based Chalcogenides as Solid Acid Fuel Cell Cathodes

Abstract

A low-cost Ru-based chalcogenide catalyst has been used as a cathode catalyst in solid acid fuel cells (SAFC). With sequential addition of Se and Mo on Ru/C in a controlled manner, the resulting physical and electrochemical properties have been discussed in detail. The oxygen reduction reaction (ORR) in the presence of phosphoric acid has been performed to appraise the tolerance of the catalyst in the presence of phosphate anions. Considering the phosphate-rich environment during cell operation, this study is especially relevant for designing catalysts for s. In order to estimate the coverage of phosphate anions on active sites, a semiquantitative analysis of the corresponding Tafel plots has been done. Electrochemical, thermogravimetric, and in situ X-ray absorption spectroscopic experiments have been performed to get a deeper perception of the catalyst–electrolyte interface and account for the high stability of the chalcogenide catalyst at room temperature as well as at elevated temperature. Steady-state polarization curves in SAFC have been collected for over 120 h using the chalcogenide catalyst operating at 250 °C.