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, cilt.5, sa.2, ss.1020-1026, 2015 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 5 Sayı: 2
  • Basım Tarihi: 2015
  • Doi Numarası: 10.1021/cs501585k
  • Dergi Adı: ACS CATALYSIS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1020-1026
  • İstanbul Teknik Üniversitesi Adresli: Hayır

Özet

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.