Compatibility of platinum with alkaline sulfide fuel: Effectiveness and stability of platinum as an anode catalyst in direct alkaline sulfide fuel cell

Abstract

Exposure of Pt/C catalyst to sulfur-containing compounds has been avoided due to sulfur-induced deactivation of the catalyst. In this study, an aqueous alkaline sulfide medium, which was expected to provide an electrolyte environment that prevents Pt/C surface from poisoning, was selected as a fuel for direct alkaline sulfide fuel cell (DASFC) and its compatibility with Pt/C was evaluated. Pt/C was indeed shown to be an effective anodic catalyst for oxidizing sulfide, and the maximum power density of 39.20 mW cm(-2) was recorded at 1 M Na2S, 3 M NaOH, and at 70 degrees C with Pt/C loading of 5 mg cm(-2). 30 h life test under highly sulfidic condition neither resulted in any appreciable drop in cell performance, nor caused irreversible formation of PtS or PtS2, ensuring not only performance stability and but also chemical stability of Pt/C in alkaline sulfide fuel. This study supports the possibility that like common fuel cell systems DASFC can benefit from the use of the powerful catalyst Pt.