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

Abstract

A series of Pt 50 Ni 50 supported on MCM-41 catalysts were prepared via wet co-impregnation of the metal salts H 2 PtCl 6 and NiSO 4 Á6H 2 O. The metal salts were reduced using NaBH 4 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, NaBH 4 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 NaBH 4 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 Pt 50 Ni 50 with that of the respective monometallic catalysts synthesized at optimum conditions, show that the Pt 50 Ni 50 exhibited superior reactivity. Surface properties of the catalysts were characterized using H 2 -TPR, H 2 -adsorprtion and H 2 -TPD analyzes. Studies on the morphology of the metal particles and composition were obtained via TEM and SEM equipped with elemental analysis.

Effect of oxide supports in stabilizing desirable Pt–Ni bimetallic structures for hydrogenation and reforming reactions

“…Bimetallic catalysts have been utilized in many reactions such as hydrogenation, dehydrogenation, and reforming due to their unique properties that are distinctly different from those of the corresponding monometallic catalysts. [1][2][3][4][5][6][7] Many experimental and theoretical studies have been performed to determine the activity and stability of bimetallic systems on well-defined single crystal surfaces. 4,8,9 It has been demonstrated that the structural and electronic properties of bimetallic surfaces strongly affect catalytic performance.…”

Highly dispersed platinum nanoparticles on mesoporous materials

“…Surface functionalization of MCM-41 also helps for quantitative and high dispersion of Pt nanoparticles. Up to now, siliceous MCM-41 [32], Ti-MCM-41 [33], Al-MCM-41 [29], Fe-MCM-41 [34], V-MCM-41 [35], other metalloaded MCM-41 [36] and amine-functionalized MCM-41 materials [37] have been used as supported materials for high dispersion of Pt nanoparticles. Moreover, bimetallic nanoparticles supported on amine-functionalized MCM-41 and Al-MCM-41 were also used for isomerization and hydrocracking of n-decane [38,39].…”