Dehydrogenation of a liquid organic hydrogen carrier compound 1-(3-cyclohexylpropyl)-3-ethylcyclohexane: A density functional theory study

Abstract

As a compound for liquid organic hydrogen carrier (LOHC) applications, 1-(3-cyclohexylpropyl)-3-ethylcyclohexane was designed and its dehydrogenation reaction was investigated using density functional theory calculations. To check how this compound could be stable, vibrational frequency analysis and formation energy calculations were conducted. Our findings revealed that this LOHC compound was dynamically and chemically stable. Using Mulliken population analysis, the dehydrogenation process was clearly explained. To reduce the dehydrogenation energy, different substituents, such as N, Cl, and Br were used. Our results suggested that N-substitution could be potentially suitable to lower the dehydrogenation energy. Reaction barriers of pristine and N-substituted systems for dehydrogenation reactions were investigated through nudged elastic band methods. In addition, the gap between HOMO and LUMO was calculated to check chemical reactivity.