Hydrogenation of Succinic Anhydride by Nickel-Molybdenum Catalyst Supported on SiO₂-Al₂O₃-Composition and Activity of Catalyst-

Abstract

Reduced nickel-molybdenum supported on SiO2-Al2O0 was found to be a favorable catalyst for the production of tetrahydrofuran and T-butyrolactone from succinic anhydride or maleic anhydride.The favorable composition ratio of Mo to Ni range from 0.06 to 0.2. SiO2-A1203 and kieselguhr were used as the catalystsupport, and the former was better than the latter with respect to both the activity and selectivity for the production of tetrahydrofuran.
It was confirmed by X-ray diffraction for the catalyst of various composition that molyb- denumwas incorporated into the nickel crystal forming a solid solution with nickel. Simple relations were found among the Mo/Ni atomic ratio, the crystal size and the lattice constant of Ni(III) plaine. The catalytic activity increased with increase in the lattice constant and decreased with increase in the crystal size. Itmay be concluded that the lattice constant and crystal size affect the characterand number of active center of catalyst, respectively. Not only the composition ofcatalyst but also the temperature, hydrogen flow rate and water content ofreducing gases in the reduction procedure of catalyst influenced the nature of the ystal of Ni(III) plaine and the catalytic activity. The most favorable reductiontemperature was ranged from 600 to 8000C.