In recent years, liquid hydrogen has been at the forefront of sustainable energy research around the globe. Hydrogen is used in many industrial processes, and also as a fuel. When used in a fuel cell, hydrogen creates two byproducts: water and heat; no greenhouse gases or toxic pollutants are emitted. Despite its efficacy, liquid hydrogen must be kept under high pressures and extremely cold temperatures to be stored and transported. To be used in existing fuel infrastructures like gas pipelines or tankers, hydrogen must be stored alternatively. Through reversible catalytic hydrogenation and dehydrogenation of organic molecules, called liquid organic hydrogen carriers (LOHCs), liquid hydrogen can be more easily commercially used. Catalysts are necessary to facilitate the dehydrogenation and hydrogenation of LOHCs, and typical catalysts include platinum and palladium. Because pure forms of these metals are not optimal catalysts on their own, they can be doped with various modifiers to enhance their utilization. This study investigates the effects of P, Cl, and F on the methylcyclohexane/toluene system over Pt using density functional theory (DFT) calculations. DFT is a computational modeling method used to investigate the electronic structure of multi-particle systems such as this catalytic system. By iterating over the molecular geometry and solving a quantum mechanical equation for the system, the most energetically favorable molecular geometry is found when the energies of the system converge. This study showed that different dopants rely on different mechanisms, such as blocking and hydrogen bonding, to change the adsorption energies of toluene and methylcyclohexane. Future work may explore the effects of dopants on the demethylation reaction from toluene to benzene or the reaction kinetics of dehydrogenation.