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Abstract: We have studied the reactivity towards dihydrogen of Ni2+–Ni+ reduced ions, residing above two framework oxygen atoms, using a 18 SiO4 tetrahedrals (18T) model cluster representing the intersection of the straight and the sinusoidal channels in ZSM-5 zeolite. Reported are a detailed analysis of the Ni+–H2 orbital interactions, the thermodynamic stability, and characteristic spectral signatures of the predicted Ni+(H2) n nonclassical hydrides for n =1 and 2, at the B3LYP level of theory. Comparison is made to existing spectroscopy data for a Ni+(H2) complex formed in Ni-exchanged ZSM-5 zeolite . [Copyright &y& Elsevier]

Abstract: Quantum chemical calculations including DFT, MP2, MP4 and QCISD predict the formation of non-classical η2-hydride of Ag+ coordinated to two oxygen atoms, in the frameworks of various zeolites. These model calculations are compared with existing zeolite structural data, other modelling works, and Inelastic Neutron Scattering (INS) spectroscopy data of dihydrogen adsorbed in a Ag-exchanged zeolite with LTA topology. It is also found that, although a little less stable, the corresponding η2-H2–Ag+ exist as well in the gas phase. [Copyright &y& Elsevier]

The structural properties of two mechanically activated commercial LaNi5 type battery materials and their deuterides have been investigated by means of in situ neutron powder diffraction analysis. A discussion of the hysteresis between the absorption and desorption isotherms is given. Using standard Rietveld refinement procedures, information on the variation of the deuterium site occupancy, the lattice symmetry and the cell volume are also presented. In particular, we report on the variation of line-broadening with concentration as well as on the complex time-dependent changes in the lattice parameters and the line-broadening following a step change in the deuterium pressure. We then show that these relatively novel data provide valuable information on the rather different phase transition processes observed for the two materials and offer an explanation for the superior kinetics of the AB4.8 alloy. [Copyright &y& Elsevier]