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Adsorption and dissociation of hydrogen peroxide on small Pd xM3-x (M = Pt, Cu; X = 1-3) clusters: A hybrid density functional study

Nahali, M ; Sharif University of Technology | 2011

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  1. Type of Document: Article
  2. DOI: 10.1080/00268976.2011.592862
  3. Publisher: 2011
  4. Abstract:
  5. The adsorption and dissociation of H2O2 on small PdxM3-x (M=Pt, Cu; x = 1-3) clusters is investigated using the B3PW91 hybrid density functional method. Natural bond orbitals are analysed to obtain partial charges on atoms, dipole moments, bond orders, and hybrid orbitals of the PdxM3-x-H2O2 systems. The calculated adsorption energies are in the range of -0.32 to -2.12 eV. Generally, H2O2 adsorbs on top positions through one of its oxygen atoms and only in a few cases reacts with the cluster through both oxygen and hydrogen sides. In the latter case the cluster sites which are negatively charged interact with the hydrogen atoms. Interestingly, on the triplet Pd2Pt cluster, H2O2 dissociates spontaneously to two OH that adsorb strongly on the Pd sites. In this chemical bond the oxygen p orbitals interact with the Pd d orbitals. Surprisingly, this mode of adsorption never occurs on the singlet Pd2Pt cluster and neither on other clusters with similar charge distributions. We believe that not only the electric field of the positively charged Pd atoms but also the Pd unpaired d electrons in the triplet Pd2Pt cluster make H 2O2 dissociative adsorption to be thermodynamically and kinetically favoured
  6. Keywords:
  7. Dissociation ; Adsorption energies ; Bond orders ; Cluster sites ; D electrons ; D orbitals ; DFT ; Dissociative adsorption ; Hybrid density functional ; Hybrid density functional method ; Hybrid orbitals ; Hydrogen atoms ; Natural bond orbital ; Orbitals ; Oxygen atom ; Partial charges ; Pd atoms ; Positively charged ; Pt clusters ; Small clusters ; Adsorption ; Atoms ; Chemical bonds ; Electric fields ; Hydrogen ; Hydrogen peroxide ; Oxidation ; Oxygen ; Palladium ; Photodissociation ; Platinum ; Platinum compounds
  8. Source: Molecular Physics ; Volume 109, Issue 14 , May , 2011 , Pages 1797-1804 ; 00268976 (ISSN)
  9. URL: http://www.tandfonline.com/doi/abs/10.1080/00268976.2011.592862