Hydrogen-donor solvent

A hydrogen-donor solvent is hydrocarbon that transfers hydrogen to hydrogen-poor substrates, such as coal. The hydrogen-poor substrates could be a solute or suspension. The classic hydrogen-donor solvent (or just donor solvent) is tetrahydronaphthalene,^[1] which converts to naphthalene by transfer of two equivalents of H₂ to the substrate. The enthalpy of hydrogenation of naphthalene is relatively low, which allows the tetrahydronaphthalene to be regenerated in the presence of high pressure H₂. Catalysts are often used, such as molybdenum disulfide. Related hydrogen donor solvents or solvent components are dihydrophenanthrene and tetrahydroquinoline.^[2][3]