@article { ISI:000239884300028, title = {Theoretical study of N2O reduction by CO in Fe-BEA zeolite}, journal = {Chemphyschem}, volume = {7}, number = {8}, year = {2006}, month = {AUG}, pages = {1795-1801}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

Quantum mechanical (QM) and QM/molecular mechanics (MM) studies of the full catalytic cycle of N2O reduction by CO in Fe-BEA zeolite, that is, oxidation of BEA-Fe by NO and reduction of BEA-Fe-alpha O by CO, is presented. A large QM cluster, representing half of the channel of the BEA zeolite, is used. The contribution of the MM embedding to the calculated activation energies is found to be negligible. The minimum-energy paths for N2O decomposition and reduction with CO are calculated using the nudged elastic bond (NEB) method. Calculated band experimental activation energies ore in good agreement The two possible orientations for the gaseous molecules adsorbing on the Fe site that ore found lead to different activation energies.

}, keywords = {Density functional calculations, iron, nitrogen oxides, reaction mechanisms, zeolites}, issn = {1439-4235}, doi = {10.1002/cphc.200600228}, author = {Fischer, Gerd and Goursot, Annick and Coq, Bernard and Delahay, Gerard and Pal, Sourav} } @article { ISI:000255704100017, title = {Density functional investigations of electronics structure and dehydrogenation reactions of Al- and Si-substituted magnesium hydride}, journal = {ChemPhysChem }, volume = {9}, number = {6}, year = {2008}, month = {APR}, pages = {928-934}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

{The effect on the hydrogen storage attributes of magnesium hydride (MgH2) of the substitution of Mg by varying fractions of Al and Si is investigated by an ab initio plane-wave pseuodopotential method based on density functional theory. Three supercells, namely, 2 x 2 x x 3 x 1 x 1 and 5 x 1 x 1 are used for generating configurations with varying amounts (fractions x=0.0625, 0.1, and 0.167) of impurities. The analyses of band structure and density of states (DOS) show that, when a Mg atom is replaced by Al, the band gap vanishes as the extra electron occupies the conduction band minimum. In the case of Si-substitution, additional states are generated within the band gap of pure MgH2-significontly reducing the gap in the process. The reduced band gaps cause the Mg-H bond to become more susceptible to dissociation. For all the fractions, the calculated reaction energies for the stepwise removal of H-2 molecules from Al- and Si-substituted MgH2 ore much lower than for H-2 removal from pure MgH2. The reduced stability is also reflected in the comparatively smaller heats of formation (Delta H-f) of the substituted MgH2 systems. Si causes greater destabilization of MgH2 than Al for each x. For fractions x = 0.167 of Al

}, keywords = {band structure, Density functional calculations, hydrides, Hydrogen storage, Thermodynamics}, issn = {1439-4235}, doi = {10.1002/cphc.200700860}, author = {Kelkar, Tuhina and Pal, Sourav and Kanhere, Dilip G.} } @article { ISI:000341059100015, title = {Enhanced interaction of molecular oxygen with amino acid complexes of silver and gold clusters}, journal = {Indian Journal of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical \& Analytical Chemistry}, volume = {53}, number = {8-9, SI}, year = {2014}, month = {AUG}, pages = {996-1000}, publisher = {NATL INST SCIENCE COMMUNICATION-NISCAIR}, type = {Article}, address = {DR K S KRISHNAN MARG, PUSA CAMPUS, NEW DELHI 110 012, INDIA}, abstract = {

Density functional theory calculations have been carried out to study the effect of amino acid adsorption on the reactivity of silver and gold clusters with molecular oxygen. It is found that the amino acids glycine and alanine form stable complexes with both Ag-4 and Au-4 clusters. However, the extent of interaction is more in the case of the Au-4 cluster, as reflected from the increase in binding energy in the amino acid Au-4 complexes. Our results confirm that the adsorption of amino acids glycine and alanine enhances the reactivity of Ag-4 and Au-4 clusters towards O-2 molecule. The enhanced reactivity of O-2 molecule towards the amino acid metal cluster complexes is manifested by an increase in the O-2 binding energy and a decrease in the M-O (M = Ag, Au) bond length. Moreover, it is found that the co-adsorption of amino acids and O-2 molecule on the Ag-4 and Au-4 clusters is cooperative.

}, keywords = {Amino acid complexes, Density functional calculations, Gold clusters, Metal clusters, Silver clusters, Theoretical chemistry}, issn = {0376-4710}, author = {Manzoor, Dar and Pal, Sourav} }