Highly strained gold (Au)-palladium (Pd) core-shell nanobipyramids with extraordinary high activity and durability towards ethanol electrooxidation

Direct ethanol fuel cells (DEFCs) have emerged as promising power sources for mobile electronics due to their eco-friendly advantages over analogous devices fed with hydrogen. However, the ethanol oxidation reaction (EOR), the anode reaction of DEFCs, suffers from slower oxidation kinetics compared to the existing H2-fuel cells. Herein, we report a strategy based on maximum strain in Au@Pd core-shell nanobipyramid (NBP) structure where strain induced electronic effect enhances surface adsorption of ethanol towards boosted EOR. The novelty of construction of the present core-shell nanoparticle (NP) lies not only in showing up maximum tensile strain due to the lattice mismatch between the core (Au) and shell (Pd) atoms but also in introducing an additional amount of strain manifested by the 5-fold twins and stacking faults type defects, caused by the presence of an optimally size selected bipyramid shape Au core. Finally, we have discovered that such highly strained Au@Pd core-shell NBPs with the thinnest possible Pd shell exhibit extraordinary high electrocatalytic effect up to highest level of mass activity of 15.26 A mgPd  1 in the EOR under alkaline conditions which is superior to that of any Pdbased catalysts reported so far and commercial Pd/C catalysts.

Automated summary

This article introduces a maximum strain strategy based on Au@Pd core-shell nanobipyramids, which enhances the surface adsorption of ethanol through strain-induced electronic effect, thereby improving the efficiency of the ethanol oxidation reaction, the anode reaction of direct ethanol fuel cells (DEFCs).