Estimating Bulk-Composition-Dependent H-2 Adsorption Energies on CuxPd1-x, Alloy (111) Surfaces


Boes J. R. , Gumuslu G., Miller J. B. , Gellman A. J. , Kitchin J. R.

ACS CATALYSIS, vol.5, no.2, pp.1020-1026, 2015 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 5 Issue: 2
  • Publication Date: 2015
  • Doi Number: 10.1021/cs501585k
  • Title of Journal : ACS CATALYSIS
  • Page Numbers: pp.1020-1026

Abstract

The bulk-composition-dependent dissociative adsorption energy of hydrogen on CuPd alloys has been measured experimentally and modeled using density functional theory. The hydrogen adsorption energy cannot be simply defined by a single reactive site or as a composition weighted average of the pure metal components. We developed a modeling approach that uses a basis of active sites weighted by a model site probability distribution to estimate a bulk-composition-dependent adsorption energy. The approach includes segregation under reaction conditions. With this method, we can explain the composition-dependent adsorption energy of hydrogen on Cu-rich alloy surfaces. In Pd-rich alloys, a Pd-hydride phase may form, which results in deviations from trends on the metallic alloy surface.