A theoretical study of the mechanism of oxidative dihydrogen addition to palladium clusters

Kinetic isotope effects in the activation of HH bonds by palladium clusters

“…11 The H 2 addition to the Pd 2 cluster is known to occur without a potential-energy barrier. [6][7][8][9] It was found 9,12 that the results of CNDO/S 2 calculations of the structures of the stationary points of the PESs of the H-H bond activation by both the Pd atom and the Pd 2 cluster are in a good agreement with the data of ab initio calculations that took into account correlation and relativistic effects. According to our CNDO/S 2 calculations for the 1 Σ g + state of a Pd 2 cluster, the equilibrium Pd-Pd distance is equal to 2.93 Å; w Q(Pd-Pd) = 103 cm -1 ; the dissociation energy D 0 = 16.7 kJ mol -1 .…”

“…Mamaev et al 9 analysed the PES of the oxidative H 2 addition to the Pd 2 cluster within the reaction-path Hamiltonian (RPH) approximation 10 on the basis of the semiempirical CNDO/S 2 method. 11 The H 2 addition to the Pd 2 cluster is known to occur without a potential-energy barrier.…”

A theoretical study of the catalytic cycle of ethylene hydrogenation by a bipalladium cluster

“…Reaction (1) was studied in detail elsewhere. 14 In further studies, we found that species I cannot add an ethylene molecule with hydrogen atom transfer, and it forms only an adsorption complex. trans-Form II was found to be active in the propagation of the catalytic cycle.…”

“…The aim of this work was to study theoretically the catalytic cycle of ethylene hydrogenation with the Pd 2 cluster. Previously, 14 we used the reaction-path Hamiltonian (RPH) approximation 15 for studying in detail the oxidative addition of the H 2 molecule to the Pd 2 cluster. We found that the potential-energy surface of this reaction exhibits a complex shape with several valleys and stationary points.…”

“…We repeatedly used the above technique for studying the activation of H-H and C-H bonds by the Pd atom and the Pd 2 cluster. 7,14 Additional calculations were performed for the main stationary points of the PES using the DFT method in two approximations for exchange correlation energy (DFT-BLYP 17 and DFT-PBE 18 ), which were implemented in the program. 19 A detailed study of the PESs of reactions ( 1) and ( 2) by the CNDO/S 2 technique based on the RPH approach allowed us to separate five interrelated RPs (RP 1 , RP 2 , RP 3 , RP 4 and RP 5 ), elementary steps of the full catalytic cycle.…”