Pt nanoparticles for improving the performance and durability of Fe-N-C based materials towards oxygen reduction reaction in alkaline direct methanol fuel cells

Abstract

Pt-alloy nanoparticles have been reported to enhance the oxygen reduction reaction (ORR) durability and boost Pt methanol tolerance. In this work, we have studied two different Pt-Fe-N-C based materials, where one of the carbon materials is derived from a biomass residue (almond shell), prepared by standard impregnation and NaBH₄ reduction or one-pot high-temperature treatment. The materials were characterized in terms of methanol tolerance, accelerated durability tests, power density in membrane electrode assembly (MEA) configuration, and stability (100 h). The results showed that, although the particle size distribution obtained for the one-pot synthesis was wider, an effective modification of the Pt structure was observed, which was translated into a higher methanol tolerance. When a small amount of platinum was incorporated in the biomass-derived Fe-N-C catalysts, and tested for the first time (to the best of our knowledge) in alkaline direct methanol fuel cell (ADMFC), significant improvement in durability under ORR conditions was achieved, which finally resulted in superior performance in MEA configuration.