%0 Journal Article %1 hlwoodcock:Q.1998c %A Cui, Q. %A Musaev, D. G. %A Morokuma, K. %D 1998 %J J. Phys. Chem. A %K atoms dehydrogenation basis functions gaussian theory energies electronic-structure density-functional first-row atomic platinum sets dynamics bibtex-import clusters cations %N 31 %P 6373--6384 %T Molecular orbital study of h-2 and ch4 activation on small metal clusters. 2. pd-3 and pt-3 %V 102 %X The electronic structure of Pd-3 and Pt-3 clusters and the detailed reaction mechanism of activation of H-2 and CH4 on these clusters have been studied with a density functional method. Full geometry optimization has been carried out and led to the reaction mechanisms that are dramatically different from those of a previous work where only limited potential energy scans were carried out. In the Pd-3 + H-2 system, Pd-3, like Pd-2, activates H-2 without barrier. For the activation of the C-H bond in CH4 with Pd-3, although the final products are found to be similar in energy compared to the case of Pd-2, the activation barriers on Pd-3 are much higher than those on Pd-2. This difference has been explained in terms of the large repulsion from the s(1)d(9) configurations of Pd atoms in Pd-3, whereas Pd atoms in Pd-2 adopt mainly the less repulsive d(10) configuration. In the case of Pt-3 + H-2/CH4, the reactions basically follow the same pattern as in the Pt-2 systems. Namely H-H and C-H are broken at first on a single Pt atom, and then one H atom migrates to other Pt atom(s). No activation barrier has been found on either the singlet or the triplet state for H-H activation, and a smaller activation barrier height compared to the Pt-2 case has been obtained for the C-H activation. Results from the current series of studies are consistent with the recent experimental observations on the reactivities of unsupported Pd-n and Pt-n.

@article{hlwoodcock:Q.1998c, abstract = {The electronic structure of Pd-3 and Pt-3 clusters and the detailed reaction mechanism of activation of H-2 and CH4 on these clusters have been studied with a density functional method. Full geometry optimization has been carried out and led to the reaction mechanisms that are dramatically different from those of a previous work where only limited potential energy scans were carried out. In the Pd-3 + H-2 system, Pd-3, like Pd-2, activates H-2 without barrier. For the activation of the C-H bond in CH4 with Pd-3, although the final products are found to be similar in energy compared to the case of Pd-2, the activation barriers on Pd-3 are much higher than those on Pd-2. This difference has been explained in terms of the large repulsion from the s(1)d(9) configurations of Pd atoms in Pd-3, whereas Pd atoms in Pd-2 adopt mainly the less repulsive d(10) configuration. In the case of Pt-3 + H-2/CH4, the reactions basically follow the same pattern as in the Pt-2 systems. Namely H-H and C-H are broken at first on a single Pt atom, and then one H atom migrates to other Pt atom(s). No activation barrier has been found on either the singlet or the triplet state for H-H activation, and a smaller activation barrier height compared to the Pt-2 case has been obtained for the C-H activation. Results from the current series of studies are consistent with the recent experimental observations on the reactivities of unsupported Pd-n and Pt-n.}, added-at = {2006-06-16T05:03:46.000+0200}, author = {Cui, Q. and Musaev, D. G. and Morokuma, K.}, biburl = {https://www.bibsonomy.org/bibtex/26e4882433cebf06a3bf6c1633d8a4547/hlwoodcock}, citeulike-article-id = {569414}, comment = {108QT J PHYS CHEM A}, interhash = {0a6eb8ed0dd5270986b33614d526fa84}, intrahash = {6e4882433cebf06a3bf6c1633d8a4547}, journal = {J. Phys. Chem. A}, keywords = {atoms dehydrogenation basis functions gaussian theory energies electronic-structure density-functional first-row atomic platinum sets dynamics bibtex-import clusters cations}, number = 31, pages = {6373--6384}, priority = {2}, timestamp = {2006-06-16T05:03:46.000+0200}, title = {Molecular orbital study of h-2 and ch4 activation on small metal clusters. 2. pd-3 and pt-3}, volume = 102, year = 1998 }