Core/shell nanoparticles (NP) represent a promising class of catalysts in energy conversions. We have proposed a multiscale computational strategy to design core/shell NPs for electrocatalysis. A universal relation between surface strain and oxygen adsorption energy on NPs is established based on which one can computationally screen and design core/shell NP catalysts for superior ORR activities. This strategy is first applied to Pt-based core/shell NPs, and Fe−Pd, Co−Pd, and Ni−Pd alloys are predicted as promising candidates for the core materials. We have systematically examined the effect of particle shape, size, thickness and chemical composition on ORR activities for Pd-based core/shell NPs. The NPs possess under-coordinated facets and elastic strains, both are beneficial to ORR activities. Based on the same principle, we propose penta-twinned Cu nanowires (NWs) as excellent candidates for CO2 electroreduction. The penta-twinned NWs possess a combination of ultrahigh mechanical strength, large surface-to-volume ratios and an abundance of under-coordinated adsorption sites, all desirable for CO2 electroreduction. In particular, we show that the NWs can withstand elastic strains orders of magnitude higher than their conventional counterpart, and as a result their CO2 electroreduction activities can be significantly enhanced by elastic tensile strains. With a moderate tensile strain, the bias potential for methane production at a decent current density can be reduced by 50%.

Computational design of nanoparticles and nanowires for electrocatalysis

251st National Meeting (2016)

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