Enhancing Selectivity in LOHC Systems: A Thermodynamic Analysis of Toluene-Methylcyclohexane

Various systems have been extensively studied for use as Liquid Organic Hydrogen Carriers (LOHCs), including methylcyclohexane/toluene (6.1 wt % theoretical hydrogen storage capacity)[20], cyclohexane/benzene (7.14 wt %)[21], decalin/naphthalene (7.3 wt %)[22], and perhydro-dibenzyltoluene/dibenzyltoluene (6.2 wt %)[23]. A key challenge in these systems lies in achieving high selectivity during (de)hydrogenation reactions. The formation of undesirable intermediate compounds can significantly impact the efficiency of hydrogen storage and release. Resolving this selectivity challenge presents a significant opportunity for the discovery of innovative and more efficient LOHCs.

To illustrate this challenge and explore potential solutions, this article focuses on the thermodynamics of the hydrogenation-dehydrogenation reaction of toluene and methylcyclohexane (MCH). By understanding the thermodynamic factors governing selectivity in this reaction, researchers can develop strategies and catalysts to enhance the performance of LOHC systems for practical hydrogen storage and transportation applications.