Modulating Electronic Structure Of An Au-Nanorod-Core-Pdpt-Alloy-Shell Catalyst For Efficient Alcohol Electro-Oxidation

Direct alcohol fuel cells (DAFCs) utilize alcohol electro-oxidation reactions (AORs) to provide electricity, where catalysts with optimal electronic structures are required to accelerate sluggish AORs. Herein, an electrocatalyst with an Au-nanorod core and a PdPt-alloy shell is designed. Its electronic structures are modulated through epitaxial growth of a PdPt-alloy shell on the Au-nanorod core, which exhibits a tensional strain effect and atomic steps. Three key problems of AORs are solved with this catalyst, including poor adsorption of alcohols on the catalyst, CO poisoning of the catalyst, and a high free energy barrier for the AORs. Taking methanol electro-oxidation reaction (MOR) as an example, this catalyst shows 9.4 times higher mass activity than the market-available Pt/C catalyst. Theoretic simulations prove that this catalyst has a low free energy barrier for the MOR, and strong adsorption of methanol but weaker adsorption of carbonaceous intermediates. The reasons behind this are the stretched geometric structure of the PdPt (100)-alloy shell and the optimized electronic structure of catalytic sites on the catalyst surface. Meanwhile, efficient electro-oxidation of ethanol, ethylene glycol, and glycerol is realized. This work paves the way to design and synthesize universal and efficient AOR catalysts for the construction of high-performance DAFCs.