Improved H2 uptake capacity of transition metal doped benzene by boron substitution. Issue 52 (12th May 2016)

• Record Type: Journal Article
• Authors: Deshmukh, Amol; Konda, Ravinder; Kalamse, Vijayanand; Chaudhari, Ajay
• Is Part Of: RSC advances. Volume 6:Issue 52(2016)
• Page Start: 47033
• Page End: 47042
• Publication Date: 2016-05-12
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra06483c
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : The effect of boron substitution on hydrogen storage capacity of transition metal (TM) doped benzene is studied using density functional theory and the second order Møller–Plesset method with aug-cc-pVDZ basis set. Abstract : The effect of boron substitution on hydrogen storage capacity of transition metal (TM) doped benzene is studied using density functional theory and the second order Møller–Plesset method with aug-cc-pVDZ basis set. Out of the six carbon atoms in a benzene ring, two are substituted by boron atoms. The structures considered here are C4 B2 H6 TM (TM = Sc, Ti, V). Four, four and three H2 molecules can be adsorbed on unsubstituted C6 H6 Sc, C6 H6 Ti and C6 H6 V complexes, respectively, whereas upon boron substitution one additional H2 molecule gets adsorbed on each of these complexes. The H2 uptake capacity of C4 B2 H6 Sc, C4 B2 H6 Ti and C4 B2 H6 V obtained is 7.71, 7.54 and 5.99 wt%, respectively. Gibbs free energy corrected adsorption energies show that H2 adsorption on C4 B2 H6 Sc is energetically unfavorable whereas it is favorable on C4 B2 H6 Ti and C4 B2 H6 V at ambient conditions. Various interaction energies for the H2 adsorbed complexes are obtained using a many-body analysis technique. The H2 desorption temperature for boron substituted TM doped benzene is lower than that for TM doped benzene for all the three systems. Molecular dynamics simulations show that loosely bonded H2 molecules in C4 B2 H6 Sc(5H2 ) and C4 B2 H6 Ti(5H2 ) complexes fly away during the simulation, thereby showing lower H2 uptake capacity of these complexes than that obtained by electronic structure calculations.