Conversion of butyronitrile to butylamines on noble metals: effect of the solvent on catalyst activity and selectivity

Abstract

The liquid-phase hydrogenation of butyronitrile to butylamines was studied on Pt(0.27%)/SiO₂, Pd(0.33%)/SiO₂ and Ru(1.80%)/SiO₂ using n-butanol, toluene and cyclohexane as solvents. In n-butanol, Pt and Pd catalysts formed preponderantly dibutylamine and minor amounts of tributylamine while Ru/SiO₂ yielded mainly butylamine. Replacing n-butanol by toluene or cyclohexane caused significant changes in catalyst activity and selectivity. These changes were interpreted by relating the catalyst performance with the solvent–catalyst interaction strength that was investigated by temperature-programmed desorption of solvents and mass spectrometry. Pd/SiO₂ was strongly deactivated with the progress of the reaction in all the solvents.