Synthesis, characterization and n-hexane hydroisomerization performances of Pt supported on alkali treated ZSM-22 and ZSM-48. Issue 51 (14th August 2018)

• Record Type: Journal Article
• Authors: Li, Haoran; Liu, Chenglian; Wang, Yan; Zheng, Jiajun; Fan, Binbin; Li, Ruifeng
• Is Part Of: RSC advances. Volume 8:Issue 51(2018)
• Page Start: 28909
• Page End: 28917
• Publication Date: 2018-08-14
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8ra04858d
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : ZSM-48 and ZSM-22 zeolites with similar Si/Al molar ratio have been treated with alkali to modify the pore structures and acidity, and they have been characterized by XRD, SEM, TEM, N2 adsorption/desorption, NMR, NH3 -TPD and Py-FTIR. Abstract : ZSM-48 and ZSM-22 zeolites with similar Si/Al molar ratio have been treated with alkali to modify the pore structures and acidity, and alkali treated ZSM-22 and ZSM-48 samples have been characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), N2 adsorption/desorption, Nuclear Magnetic Resonance (NMR), NH3 -Temperature Programmed Desorption (NH3 -TPD) and Pyridine-Fourier Transform Infrared Spectroscopy (Py-FTIR). Characterization results indicate that NaOH treatment could improve the mesoporous structure for both ZSM-22 and ZSM-48. NaOH treatment modifies the acidity of ZSM-22 and ZSM-48 diversely. The n -hexane hydroisomerization performances of Pt supported protonic form ZSM-22 and ZSM-48 (Pt/HZSM-22 and Pt/HZSM-48) bifunctional catalysts have been evaluated in a fixed bed reactor. Catalytic results indicate that catalytic activity and selectivity depend on both pore structure and acidity of zeolites. In comparison of Pt/HZSM-22 and Pt/HZSM-48, Pt/HZSM-22 shows better n -hexane hydroisomerization performance at relatively low temperature (<300 °C), meanwhile, at relatively high temperature (>300 °C) Pt/HZSM-48 exhibits better catalytic performance. Moreover, alkali treated Pt/HZSM-48 could produce more di-branched isomer compared with alkali treated Pt/HZSM-22.