title: Combination of supported bimetallic rhodium-molybdenum catalyst and cerium oxide for hydrogenation of amide.
abstract: Hydrogenation of cyclohexanecarboxamide to aminomethylcyclohexane was conducted with silica-supported bimetallic catalysts composed of noble metal and group 6-7 elements. The combination of rhodium and molybdenum with molar ratio of 1:1 showed the highest activity. The effect of addition of various metal oxides was investigated on the catalysis of Rh-MoOx/SiO2, and the addition of CeO2much increased the activity and selectivity. Higher hydrogen pressure and higher reaction temperature in the tested range of 2-8 MPa and 393-433 K, respectively, were favorable in view of both activity and selectivity. The highest yield of aminomethylcyclohexane obtained over Rh-MoOx/SiO2+ CeO2was 63%. The effect of CeO2addition was highest when CeO2was not calcined, and CeO2calcined at >773 K showed a smaller effect. The use of CeO2as a support rather decreased the activity in comparison with Rh-MoOx/SiO2. The weakly-basic nature of CeO2additive can affect the surface structure of Rh-MoOx/SiO2, i.e. reducing the ratio of Mo-OH/Mo-O-sites.
authors.affiliation: Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Nakagawa
authors.affiliation: Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
authors.forename: Riku
authors.initials: R
authors.lastname: Tamura
authors.affiliation: Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
authors.forename: Masazumi
authors.initials: M
authors.lastname: Tamura
authors.affiliation: Department of Applied Chemistry, School of Engineering, Tohoku University, 6-6-07, Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Tomishige
keywords: amide; amine; ceria; heterogeneous catalysis; rhodium