A special carbon core@Au/Pd shell structure catalyst: Au–Pd layer on the mesoporous carbon microsphere for enhanced activity of ethanol electro-oxidation

The design of efficient electrocatalysts for ethanol oxidation is essential for commercializing direct ethanol fuel cells (DEFCs). In this strategy, a mesoporous carbon microsphere (MC) was first synthesized by inverting the micro-emulsion technique. The MC@Au/Pd catalyst with a particular core-shell structure was obtained by utilizing mesoporous carbon as a core to load the Au/Pd layer. The novelty of the MC@Au/Pd catalyst with specialized core-shell structures lies not only in the high specific surface area inherited from the carbon core but also in the strong electronic interactions caused by the lattice mismatch between the core (Au) and shell (Pd) atoms. Particularly, electrochemical measures demonstrated that the Au/Pd catalyst exhibits superior catalytic activity toward the ethanol oxidation reaction (EOR) compared with commercial Pd/C catalysts. This is mainly due to the high specific surface area and mesoporous pore size inherited from the core carbon microspheres. In addition, the mesoporous carbon core and Au/Pd shell in the well-organized core-shell catalyst (MC@Au/Pd) influence the catalytic activity for ethanol oxidation by adjusting the electronic structure of Pd.