A DFT Study of Palladium Clusters and their Reactions with H2 and O2: Application to catalyzed H2O2 synthesis
Abstract
Adsorption of oxygen and hydrogen in both atomic and molecular forms on small Pdn, clusters (n=2-13 and 19) is investigated using density functional theory. An extensive search for the energetically preferred structural forms and spin states of the clusters is performed. The geometries and energetics of the cluster-adsorbate systems and their transition states are mapped out as well. Cases of both single and multiple adsorptions are considered, and trends in the saturation coverage of the clusters versus cluster size are examined. Edge sites are found to be energetically preferred for O2 adsorption, whereas the atop sites favor binding of H2. Atomic adsorption of hydrogen is examined as well and limits to the number of H atoms that can be dissociated on each size cluster are found. In order to understand how trends in the results extend to larger cluster sizes, limited calculations have also been performed for Pd55. The role of Pdn clusters as catalysts for production of H2O2 from H2 and O2 is discussed as well.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- February 2012
- Bibcode:
- 2012APS..MAR.K1232P