Thermodynamic assessment of carbazole-based organic polycyclic compounds for hydrogen storage applications via a computational approach. (5th July 2018)

• Record Type: Journal Article
• Authors: Shin, Byeong Soo; Yoon, Chang Won; Kwak, Sang Kyu; Kang, Jeong Won
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 27(2018)
• Page Start: 12158
• Page End: 12167
• Publication Date: 2018-07-05
• Subjects: Hydrogen storage -- Liquid organic hydrogen carriers -- Reaction enthalpy -- Thermodynamic assessment; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.04.182
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Liquid organic hydrogen carriers (LOHCs) are promising candidates for storage and transport of renewable energy due to their reversible reaction characteristics. For the proper assessment of candidate molecules, various thermochemical properties are required, and significant experimental efforts are necessary. In this work, we suggest a systematic method for the estimation of thermochemical properties for LOHC candidate molecules combining Density Functional Theory (DFT) calculations, Conductor-like Screening Model (COSMO) and Molecular Dynamics (MD) simulations. We applied the suggested method for the assessment of previously reported LOHC materials. Based on the analysis, new candidates of carbazole-derivative compounds ( N -acetylcarbazole, N -phenylcarbazole, N -benzoylcarbazole, and 4-methyl-4H-benzocarbazole) are suggested, and their properties are estimated and reviewed. Calculation results show that these candidates can provide high theoretical hydrogen uptake capacities above 6 wt% and optimal heats of dehydrogenation in the liquid phase. Analysis on the stereoisomerism showed that the structure-selectivity toward less stable stereoisomers of the hydrogen-rich form is preferable for the dehydrogenation process. Graphical abstract: Highlights: The existing LOHCs were re-evaluated in terms of thermodynamics. A new types of carbazole-derivative compounds are proposed as LOHCs. All proposed candidates satisfy the thermodynamic standards. Unstable isomers of hydrogen-rich form showed thermal efficient for dehydrogenation.