98%
921
2 minutes
20
The comprehensive utilization of iron ore tailings (IOTs) not only resolved environmental problems but also brought huge economic benefits. In this study, the synthetic route presented herein provides a novel method for the synthesis of ZSM-5 microspheres from IOTs. The effects of Si/Al molar ratios and the pH of the precursor solution on the formation of zeolite was evaluated by various analytical methods. The catalytic performance of the catalyst prepared by the solid-phase conversion method (denoted as MP-ZSM-5) was evaluated by methanol-to-propylene (MTP) reaction. Compared with the zeolite catalyst that synthesized via the conventional hydrothermal method (denoted as HM-ZSM-5), MP-ZSM-5 not only prolongs catalytic lifetime from 18.7 to 36.0 h but also has higher selectivity for propylene by MP-ZSM-5 (43.7%) than that for HM-ZSM-5 (38.6%). In addition, Kissinger-Akahira-Sunose (KAS) model is applied to the TG result to study the template removal process kinetics. The average activation energy values required for the removal of CTAB and TPABr are 201.11 ± 13.42 and 326.88 ± 16.91 kJ∙mol, respectively. Furthermore, this result is well coupled with the model-free kinetic algorithms to determine the conversion and isoconversion of the TPABr and CTAB decomposition in ZSM-5, which serves as important guidelines for the industrial production process.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s11356-023-27983-2 | DOI Listing |
J Colloid Interface Sci
June 2024
Particle Engineering Laboratory, School of Chemical and Environmental Engineering, and Suzhou Key Laboratory of Novel Semiconductor-optoelectronics Materials and Devices, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou City, Jiangsu Province 215123, Peopl
Mesoporous aluminosilicates Al-SBA-15 with large pore sizes and suitable acid properties are promising substitutes to zeolites for catalytic cracking of bulky hydrocarbons without molecular diffusion limitation. The conventional processes to synthesize Al-SBA-15 are time-consuming and often suffer from low "framework" Al contents. Herein, Al-SBA-15 microspheres are synthesized using the rapid and scalable microfluidic jet spray drying technique.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
July 2023
College of Materials Science and Engineering, Taiyuan University of Science and Technology, No. 66 Waliu Road, Wanbailin District, Taiyuan, Shanxi, 030024, China.
The comprehensive utilization of iron ore tailings (IOTs) not only resolved environmental problems but also brought huge economic benefits. In this study, the synthetic route presented herein provides a novel method for the synthesis of ZSM-5 microspheres from IOTs. The effects of Si/Al molar ratios and the pH of the precursor solution on the formation of zeolite was evaluated by various analytical methods.
View Article and Find Full Text PDFTurk J Chem
June 2020
Department of Chemical Engineering, Faculty of Engineering, Middle East Technical University, Ankara Turkey.
One-step facile synthesis of boron containing ZSM-5 microspheres is developed using 1,6-diaminohexane as the structure-directing agent and cetyltrimethylammonium bromide as the mesoporogen. High boron incorporation up to Si/B ratio of 38 is achieved and evidenced by the stretching vibrations of B-O-Si at 667 cm and 917 cm using Fourier-transform infrared spectra. The morphology of the crystals resembles berry-like spheres with sizes approximately 15 μm, which is composed of aggregated nanocrystals having sizes around 450 nm, is observed using scanning electron microscopy.
View Article and Find Full Text PDFRSC Adv
October 2020
Department of Chemistry and Chemical Engineering, Applied Chemistry, Chalmers University of Technology SE-41296 Gothenburg Sweden
A novel template-free colloidal assembly method that combines colloidal zeolite (silicalite-1) suspensions in a water-in-oil emulsion with an evaporation-induced assembly process has been developed for preparing hierarchical micro-/mesoporous zeolite microspheres (MZMs). Such particles have an interconnected mesoporosity and large mesopore diameters (25-40 nm) combined with 5.5 Å diameter micropores of the zeolite nanoparticles.
View Article and Find Full Text PDFLangmuir
June 2020
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
ZSM-5 microspheres made of nanocrystals are successfully synthesized from iron ore tailings (IOTs) using a novel and environmentally friendly method, which have a well-defined microporous and mesoporous structure with a large surface area and high acidic strength. In the absence of the liquid water phase during the solid-phase conversion, the phase separation between the surfactant and the solid silica phase is able to be bypassed. Compared to conventional methods, such as hydrothermal and steam-assisted conversion methods, this approach enhances the utilization of autoclaves, considerably reduces pollutants, and simplifies the synthetic process, which saves both energy and time.
View Article and Find Full Text PDF