| 초록 |
Motivated from the rapid growth in liquid organic hydrogen carriers (LOHCs) technology, first principles calculations were conducted to understand the dehydrogenation mechanism of a LOHC compound (1,1,6,6-tetracyclohexylhexane, C30H54). This study revealed that this system requires a moderate energy for the complete dehydrogenation. The effect of hetro-atom substitution, mono-atomic substitution (N) and co-substitution (B-N), on the dehydrogenation was investigated. The co-substitution of B-N atoms in this LOHC was found to be effective in reducing the dehydrogenation energy, while the nitrogen substitution was not clearly useful for the dehydrogenation. To understand the kinetics associated with each dehydrogenated step, CI-NEB calculations were performed. The dehydrogenation step of the first H2 molecule from the ring was found to be the rate-determining step. The B-N co-substitution also significantly reduced the activation energy for the dehydrogenation. The minimum energy path profile for a systematic dehydrogenation and the change in the chemical environment in each dehydrogenated step were systematically understood. |
