Ti doped [1,1,1,1] paracyclophane and its derivatives for hydrogen storage: A Computational Insight.

Ti-doped [1,1,1,1] paracyclophane(PCP) and its derivatives have been designed by substituting heteroatoms boron and nitrogen and studied their hydrogen storage properties using density functional theory. Heteroatom substitution is important for stronger Ti-binding whereas Ti-doping for light weight, almost empty d- orbital and its stronger interaction with H 2 molecules. Six configurations are obtained: PB1,PB2(boron substitution), PN1,PN2 (nitrogen substitution) and PBN1,PBN2(boron and nitrogen co-substitution). Stability of all Ti-doped structures has been confirmed using cohesive and formation energy. PCP, PB1, PB2, PN1, PN2, PNB1 and PNB2 show gravimetric hydrogen uptake capacity(adsorption energy) as 5.52(0.67),6.90(0.5),6.90(0.53),5.37(0.6),5.37(0.61), 5.48(0.7) and 5.48(0.74 eV) wt% respectively. Ti-doped boron substituted structures show required H 2 uptake capacity, suitable adsorption energy, thermodynamically favorable H 2 adsorption at ambient conditions, moderate desorption temperature, structural and thermodynamic stability, thus more suitable for hydrogen storage than nitrogen substituted and boron and nitrogen co-substituted structures. Ti-doped boron substituted PCP is a promising reversible hydrogen storage candidate. [Display omitted] • Ti-doped B/N or B and N substituted paracyclophane(PCP) is considered for H 2 uptake. • B-substituted Ti-PCP is more suitable for H 2 storage compared to other structures. • Ti atom strongly bind with B-substituted Ti-PCP compared to other structures. • One extra H 2 gets adsorbed on each Ti on B-substituted Ti-PCP than Ti-PCP [ABSTRACT FROM AUTHOR]