The Effect of Preparation Parameters of MCM-41 Supported Pt/Ni Catalysts and their Hydrogenation Properties

Abstract

A series of Pt50Ni50 supported on MCM-41 catalysts were prepared via wet co-impregnation of the metal salts H2PtCl6 and NiSO4·6H2O. The metal salts were reduced using NaBH4 and catalytic activities of the catalysts were investigated for the hydrogenation of benzene to cyclohexane. The effect of various reduction conditions such as reduction temperature, NaBH4 concentration and the medium in which reduction was carried out was investigated. Results show that optimum catalytic activity occurs when catalysts are synthesized at 273 K using 0.3 M of NaBH4 in a medium of ethanol. The variation in reduction rate with reduction conditions influenced the metal particle morphology which effected catalytic activity. Further comparison of the reactivity of Pt50Ni50 with that of the respective monometallic catalysts synthesized at optimum conditions, show that the Pt50Ni50 exhibited superior reactivity. Surface properties of the catalysts were characterized using H2-TPR, H2-adsorprtion and H2-TPD analyzes. Studies on the morphology of the metal particles and composition were obtained via TEM and SEM equipped with elemental analysis.