Ethylene versus ethane: A DFT-based selectivity descriptor for efficient catalyst screening

Xu, Lang; Stangland, Eric E.; Mavrikakis, Manos

doi:10.1016/j.jcat.2018.03.019

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Ethylene versus ethane: A DFT-based selectivity descriptor for efficient catalyst screening

Xu, Lang·Stangland, Eric E.·Mavrikakis, Manos

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Abstract

The production of ethylene without its hydrogenation to ethane is a challenge for several catalytic processes. Here, in this study, we present a catalyst screening scheme, where the Gibbs free energy difference between the ethylene hydrogenation barrier and ethylene desorption energy is defined as a descriptor for ethylene selectivity. Using plane-wave, dispersion-corrected DFT calculations, we evaluated the descriptor values over the (111) facets of Pt, Pd, and Cu as well as a series of Pt- and Pd-based bimetallic alloys. Our predicted descriptor values indicate that the addition of a Group IB metal (Cu, Ag, or Au) to Pt or Pd improves ethylene selectivity. Ag induces the most significant improvement at 50% while Au has the strongest effect at 75% atomic composition. Pd-based alloys exhibit superior ethylene selectivity over their Pt-based counterparts. Our descriptor model offers an efficient method for the initial screening of catalysts with improved ethylene selectivity.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY 42 ENGINEERING Catalyst screening Chemistry Density functional theory Engineering Ethylene Hydrogenation Selectivity

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Xu, Lang, Stangland, Eric E., Mavrikakis, Manos. 2018-04-06. Ethylene versus ethane: A DFT-based selectivity descriptor for efficient catalyst screening. https://doi.org/10.1016/j.jcat.2018.03.019

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