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A comparative DFT study of atomic and molecular oxygen adsorption on neutral and negatively charged PdxCu3-x (x=0-3) nano-clusters

Gobal, F ; Sharif University of Technology | 2010

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  1. Type of Document: Article
  2. DOI: 10.1016/j.theochem.2010.07.042
  3. Publisher: 2010
  4. Abstract:
  5. Adsorption of molecular and atomic oxygen on neutral and negatively charged PdxCu3-x (x=0-3) nano-clusters have been studied by density functional theory. It has been observed that modes and energies of adsorption strongly depend on the charge and composition of the nano-clusters. The most stable adsorption mode for molecular oxygen on neutral Pd/Cu nano-clusters is to bridge Pd-Cu site (adsorption energy=-103.7kJmol-1) while on negatively charged nano-clusters bridging of Pd-Pd or Cu-Cu are more stable adsorption modes (adsorption energies=-140.9 and -172.9kJmol-1). Also, the most stable adsorption mode for atomic oxygen on neutral Pd/Cu nano-clusters is on the hollow site (adsorption energy=-111.9kJmol-1) while on negatively charged nano-clusters adsorption on top of Pd or Cu are the most stable adsorption modes (adsorption energies=-289.7 and -370.2kJmol-1). With increasing copper content the adsorption energy of molecular and atomic oxygen on neutral nano-clusters decrease while on negatively charged nano-clusters increase. Also, it has been shown that (I) increasing of copper content in nano-cluster and (II) adding of negative charge to nano-clusters weaken O-O bond which can increase the activity of the nano-cluster for dissociation of molecular oxygen. Moreover, it has been shown that dissociation of molecular oxygen on nano-clusters is exothermic and occurs more favorably on Pd/Cu nano-clusters compared to on Pd nano-cluster
  6. Keywords:
  7. DFT ; Nano-clusters ; Oxygen adsorption ; Pd-Cu alloys
  8. Source: Journal of Molecular Structure: THEOCHEM ; Volume 959, Issue 1-3 , 2010 , Pages 15-21 ; 01661280 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0166128010005075