H2 Interaction with C2H2TM (TM = Sc, Ti, V) Complex Using Quantum Chemical Methods
P. Tavhare a, N. Wadnerkar b, V. Kalamse c and Ajay Chaudharia
aDepartment of Physics, The Institute of Science, Fort, Mumbai-400 032, India
bSchool of Physical Sciences, S.R.T.M. University, Nanded-431 606, India
cShri Guru Gobind Singhji Institute of Engineering and Technology, Nanded-431 606, India
Received: January 4, 2016; In final form: March 28, 2016
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This work reports a comparative study of hydrogen uptake capacity of early transition metal atom (Sc, Ti and V) attached to light acetylene (C2H2) substrate. Using density functional theory and second order Møller-Plesset method, we predict that maximum of five, five and four hydrogen molecules will be adsorbed on C2H2Sc, C2H2Ti and C2H2V complex, respectively, with respective gravimetric hydrogen uptake capacity of 12.43, 12, and 9.48 wt%. All the interactions between hydrogen molecules and organometallic complex are found to be attractive. The highest occupied molecular orbital-lowest unoccupied molecular orbital gap shows that the maximum H2 adsorbed complexes are kinetically stable. The average binding energies per H2 molecule for these complexes are within the ideal range for hydrogen storage at ambient conditions. Even after maximum hydrogen molecules adsorption on C2H2TM complexes, transition metal atoms remain strongly bound to the C2H2 substrate. We have obtained temperature and pressure range over which H2 adsorption on these three complexes is energetically favorable using the Gibbs free energy corrected H2 adsorption energy.

DOI: 10.12693/APhysPolA.129.1257
PACS numbers: 88.30.R-, 31.15.A-, 31.15.E-