Synthesis and catalytic characterization of ZSM-5 zeolite with uniform mesopores prepared in the presence of a novel organosiloxane

• Published in: Microporous and mesoporous materials Vol. 248; pp. 192 - 203
• Main Authors: Song, Guoqiang, Xue, Da, Xue, Jianwei, Li, Fuxiang
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.08.2017
• Subjects: Catalysis; Hydrothermal stability; Ion-exchange; Mesoporous ZSM-5 zeolite; Organosiloxane; Ion-exchange; Hydrothermal stability; Catalysis; Organosiloxane; Mesoporous ZSM-5 zeolite
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2017.04.027

Intracrystal-mesoporous ZSM-5 zeolites of varying SiO2/Al2O3 molar ratios with different morphologies have been synthesized by employing a novel organosiloxane (OSO) as mesopore-directing template. In comparison to the previously reported ZSM-5 zeolites with mesoporosity, the mesoporous ZSM-5 zeolites obtained in this paper have high hierarchical factor (HF, 0.13–0.18), meaning that little microporosity has been consumed with abundant mesopores introduced within zeolite frameworks. The effects of tetrapropylammonium hydroxide (TPAOH), SiO2/Al2O3 molar ratios, crystallization temperature and crystallization time on the morphologies and textural properties of the products have been discussed in detail. The synthesized mesoporous ZSM-5 zeolites were characterized with X-ray diffraction (XRD), nitrogen sorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, inductively coupled plasma (ICP) optical emission spectroscopy, the temperature-programmed desorption of NH3 technique (NH3-TPD) and thermogravimetric (TG)/differential scanning calorimetry (DSC) techniques. The outstanding hydrothermal stability of mesoporous ZSM-5 zeolites have been demonstrated by the hydrothermal treatment test. The Na+ ion-exchange test exhibits obvious superiority compared to traditional ZSM-5 zeolite. And the primary catalytic performance in reaction of cracking of 1, 3, 5-tri-isopropylbenzene also exhibits excellent conversion activity and products selectivity. [Display omitted] •ZSM-5 zeolites of different SiO2/Al2O3 with intramesopores were synthesized using a novel organosiloxane as template.•The as-prepared zeolite samples possess high HF factors.•The samples display excellent hydrothermal stability and ion-exchange ability.•The zeolite samples with abundant surface acid sites exhibit great catalytic performance.