Catalytic behavior of Pt nanoparticles dealuminated Y-zeolite for some n-alkane hydroisomerization

• Main Authors: S.A. Hanafi, H.M. Gobara, M.S. Elmelawy, S.A. Abo-El-Enein, A.A. Alkahlawy
• Format: Article
• Language: English
• Published: Elsevier 2014-06-01
• Series: Egyptian Journal of Petroleum
• Subjects: Y-zeolite; Dealumination; Heptane; Hexane; Hydroisomerization; Platinum
• Online Access: http://www.sciencedirect.com/science/article/pii/S1110062114000282

Dealuminated zeolite Y-supported platinum was prepared adopting two dealumination methods, viz. fast (1, 3 and 6 h) and slow method (18 h). The content of Pt was constant at 0.5 wt% in all investigated catalysts. The prepared samples were characterized using TGA/DSC, XRD, FTIR techniques, nitrogen adsorption at −196 °C and TEM-connected with energy dispersive spectroscopy (EDS). Surface acidity was investigated via pyridine adsorption using FT-IR spectroscopy. The parent and dealuminated Y-zeolite samples were characterized by their microporous system. By increasing the dealumination time to 6 h, the increased specific surface area and total pore volume indicated a sort of pore opening taking place with an increase in the accessibility of nitrogen molecules. DSC confirmed the thermal stability of the dealuminated zeolite samples up to 800 °C. The prepared catalysts were tested through hydroisomerization reactions of n-hexane and n-heptane using a micro-catalytic pulse technique. Different catalytic behaviors could be distinguished for the dealuminated samples based on competitive reactions; hydro-isomerization, hydrocracking and cyclization. Slow dealumination leads to the most selective catalysts for hydroisomerization. n-Heptane was converted to higher extent than n-hexane; cracking process was more evident when the former was fed to the reactor.