Rational design of septenary high-entropy alloy for direct ethanol fuel cells

Promoting C-C bond cleavage of ethanol by a complete 12-electron (12e) ethanol oxidation reaction (EOR) is a grand challenge for the development of highly efficient direct ethanol fuel cells (DEFCs). Most state-of-the-art catalysts only implement the EOR in an incom-plete 4e or 2e pathway because of the poisoning of the catalysts by strongly adsorbed CO, leading to the poor output performance and low cell efficiency of DEFCs. Herein, a septenary PtPdFeCoNiSnMn high-entropy alloy (PtPd HEA) with a PtPd-rich surface but super-low platinum group metals loading was developed. We identified and proved the functions of each element in the PtPd HEA. The DEFCs assembled with the PtPd HEA (0.12 mgPtPd.cm-2) achieved a maximum power density of 0.72 W cm -2 and a durable operation for 1,200 h, which outperforms state-of-the-art catalysts for DEFCs. This work will be a design principle for nanostructured alloy development for renewable energy and sustainability applications.

Automated summary

A PtPd HEA catalyst with a PtPd-rich surface and super-low platinum group metals loading was developed, achieving a maximum power density of 0.72 W cm -2 and durable operation for 1,200 h in DEFCs. This work has important implications for the development of nanostructured alloys for renewable energy applications.