Selective Hydrogenolysis of Methylcyclopentane in the Presence of Excess Methylcyclohexane Using Ir/SiO2 Catalyst

• Published in: Journal of the Japan Petroleum Institute 2023/03/01, Vol.66(2), pp.57-67
• Main Authors: INAGAKI, Satoshi, MAEKAWA, Yuki, ORUI, Yuki, WAKATSUKI, Rikuto, NISHI, Yuko, HIYOSHI, Norihito, KUBOTA, Yoshihiro
• Format: Article
• Language: eng ; jpn
• Subjects: Boiling points; Catalysts; Cyclic compounds; Enthalpy; Ethylcyclopentane; Hydrogenolysis; Iridium; Iridium catalyst; Methylcyclohexane; Methylcyclopentane; Rhodium; Selective hydrogenolysis; Silica; Silica support; Silicon dioxide; Strain energy; Water purification
• ISSN: 1346-8804; 1349-273X
• DOI: 10.1627/jpi.66.57

Methylcyclohexane (MCH) is a promising candidate for use as a liquid organic hydrogen carrier, but is isomerized into undesirable five-membered-ring compounds with similar boiling points to MCH, so purification requires selective conversion of the five-membered-ring compounds without reaction of the MCH. We found that an Ir/SiO2 catalyst efficiently promoted the selective hydrogenolysis of methylcyclopentane (MCP), a model five-membered-ring compound, in the presence of excess MCH in the reaction system. Ir/SiO2 and Rh/SiO2 catalysts provided high conversions in the hydrogenolysis of MCP at 200 °C, whereas almost no reaction of MCH occurred. In contrast, Pt/SiO2 catalyst was almost inactive in the hydrogenolysis of both MCP and MCH at 200 °C. The difference in reactivities for the Ir/SiO2 and Rh/SiO2 catalysts can be explained by the relatively high strain energy and formation enthalpy of MCP compared to MCH. The Ir/SiO2 catalyst also preferentially promoted the hydrogenolysis of ethylcyclopentane, which is a more realistic impurity, in the presence of excess MCH.