Theoretical insight of nitric oxide adsorption on neutral and charged Pdn (n = 1-5) clusters

• Published in: International journal of quantum chemistry 2015-07, Vol.115 (13), p.837-845
• Main Authors: Begum, Pakiza, Gogoi, Pranjal, Mishra, Bhupesh Kumar, Deka, Ramesh Chandra
• Format: Article
• Language: English
• Subjects: Adsorption; Chemistry; density functional theory; electronic property; geometric configuration; Nitric oxide; NO adsorption; Physical chemistry; Quantum physics; small palladium cluster
• ISSN: 0020-7608; 1097-461X
• DOI: 10.1002/qua.24914

Density functional theory (DFT) calculations within the framework of generalized gradient approximation have been used to systematically investigate the adsorption of nitric oxide (NO) molecule on neutral, cationic, and anionic Pdn (n = 1–5) clusters. NO coordinate to one Pd atom of the cluster by the end‐on mode, where the tilted end‐on structure is more favorable due to the additional electron in the π* orbital. On the contrary, in the neutral and cationic Pd2 system, NO coordinates to the bridge site of cluster preferably by the side‐on mode. Charge transfer between Pd clusters and NO molecule and the corresponding weakening of NO bond is an essential factor for the adsorption. The NO stretching frequency follow the order of cationic > neutral > anionic. Binding energy of NO on anionic clusters is found to be greater than those of neutral and cationic clusters. © 2015 Wiley Periodicals, Inc. Neutral, cationic, and anionic Pdn clusters (n=1–5) are valuable model systems for the metal surface in the theoretical study of adsorption of gases. Size and charge of the clusters are found to have strong influence on the adsorption configurations of NO. Adsorption occurs mostly at the low coordination sites, i.e. top sites, and induces changes in the geometric and electronic properties in both the adsorbate molecule and the cluster.