The CO chemisorption on some active sites of Pd clusters:: A DFT study

The CO adsorption on Pd, Pd-2 and Pd-4 small clusters was studied using density functional methods; the theoretical results obtained here were compared with experimental vibration frequencies of CO adsorbed on supported Pd-nanoparticles. The results indicate that the CO adsorption over Pd-2 and Pd-4 clusters give CO vibration frequencies values closed to the experiment values. Also, the theoretical results for the threefold hollow sites were compared with other nanoclusters, with n > 50 atoms, where the Pd-4 cluster also give values closed to the experiment. According with the results, two and four atoms small clusters could be used to model the active interaction sites between a gas molecule like CO and Pd nanoparticle. (c) 2006 Published by Elsevier B.V.