TY - JOUR
T1 - Impurity effects on small Pd clusters
T2 - A relativistic density functional study of Pd4X, X = H, C, O
AU - Genest, Alexander
AU - Krüger, Sven
AU - Rösch, Notker
PY - 2008/8/21
Y1 - 2008/8/21
N2 - We carried out relativistic density functional calculations to investigate systematically the effect of main group element impurities H, C, and O on a Pd4 cluster. We determined a bridging coordination for Pd 4H as most stable, whereas several other local minima are energetically close. The interaction of C with Pd4 is strong enough to restructure the cluster, resulting in two Pd2 units bridged by 4-fold coordinated C, but other isomers are again almost degenerate. Nearly degenerate isomers of Pd4O exhibit 2- and 3-fold coordination of O. In the most stable structures, the binding energies of the impurities, 295 kJ/mol for Pd4H, 655 kJ/mol for Pd4C, and 367 kJ/mol for Pd4O, are large enough to allow bond breaking of common small molecules when they interact with an ensemble of Pd4 clusters. Interestingly, the noteworthy relativistic effect on the properties of Pd 4 also affects the interaction with impurity atoms. Comparison with other metals reveals similarities with Ni4X and differences from Ir4H, Ir4C, and Pt4H.
AB - We carried out relativistic density functional calculations to investigate systematically the effect of main group element impurities H, C, and O on a Pd4 cluster. We determined a bridging coordination for Pd 4H as most stable, whereas several other local minima are energetically close. The interaction of C with Pd4 is strong enough to restructure the cluster, resulting in two Pd2 units bridged by 4-fold coordinated C, but other isomers are again almost degenerate. Nearly degenerate isomers of Pd4O exhibit 2- and 3-fold coordination of O. In the most stable structures, the binding energies of the impurities, 295 kJ/mol for Pd4H, 655 kJ/mol for Pd4C, and 367 kJ/mol for Pd4O, are large enough to allow bond breaking of common small molecules when they interact with an ensemble of Pd4 clusters. Interestingly, the noteworthy relativistic effect on the properties of Pd 4 also affects the interaction with impurity atoms. Comparison with other metals reveals similarities with Ni4X and differences from Ir4H, Ir4C, and Pt4H.
UR - http://www.scopus.com/inward/record.url?scp=51049121928&partnerID=8YFLogxK
U2 - 10.1021/jp7119075
DO - 10.1021/jp7119075
M3 - Article
AN - SCOPUS:51049121928
SN - 1089-5639
VL - 112
SP - 7739
EP - 7744
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 33
ER -