Integrated Catalyst ZnNC⊂PtZn for High-performance Ethanol Electrooxidation and DEFC.

Abstract

We report here an electrocatalyst that exhibits superior performance in the electrooxidation of ethanol. The reactive centers of the catalyst have a nest-type configuration with outer Zn-NxC nest covering inner PtZn intermetallic compound nanoparticle loaded on carbon support (ZnNC⊂PtZn/C). The high-energy stepped facets of the inner PtZn nanoparticle confined and shaped by the outer Zn-NxC nest is highly active for the critical C-C bond cleavage of ethanol in oxidation, confirmed by experimental characterizations and density functional theory calculations. The catalyst shows a rare high-performance and demonstrates a mass activity of 3.7 A mgPt-1 and a Faradaic efficiency of 78.2%, following the C1 pathway of reaction and the retention of initial activity remains 97% after 5,000 cycles. The unique configuration, also mitigating the concentration polarization, endows the catalyst with innate ethanol electrooxidation property by inner-outer synergic interactions, leading to unexpected power output of an acidic direct ethanol fuel cell.