Adsorption of CO on oxygen preadsorbed neutral and charged gas phase Pd(4) clusters: A density functional study.

We present the results of a density functional calculation on adsorption of O(2), CO, and their coadsorption at various sites of neutral, cationic, and anionic Pd(4) clusters. For all the clusters, the dissociative adsorption of oxygen sitting on Pd bridge sites is found to be preferable. Both O(2) and CO binding energies are found to be higher for the anionic Pd(4) cluster followed by cationic and neutral cluster. However, binding energies of O(2) or CO in the coadsorption complexes follow the trend: anionic > neutral > cationic. (c) 2010 Wiley Periodicals, Inc.