In order to improve the sensing properties of tin dioxide gas sensor, four kinds of different SiO₂/Al₂O₃ ratio, different particle size of MFI type zeolites (ZSM-5) were coated on the SnO₂ to prepared zeolite modified gas sensors, and the gas sensing properties were tested. The measurement results showed that the response values of ZSM-5 zeolite (SiO₂/Al₂O₃ = 70, grain size 300 nm) coated SnO₂ ...

Molecular-sized micropores of ZSM-5 zeolite catalysts provide spatial restrictions around catalytic sites that allow for shape-selective catalysis. However, the fact that ZSM-5 has two main pore systems with different geometries is relatively unexploited as a potential source of additional shape selectivity. Here, we use confocal laser-scanning microscopy to show that by changing the polarity o...

Syntheses of ZSM-5 coatings on stainless steel plates were carried out via the substrate heating method. The reaction mixture was kept at temperatures below 100 C, while the metal plates were heated to temperatures above 100 C. It was demonstrated that continuous ZSM-5 coatings of different textures with different crystal morphologies and void fractions could be formed. ZSM-5 coatings were char...

A series of supported phosphotungstic acid (H3PW12O40, HPW) catalysts, including HPW/β, HPW/Sn-β, HPW/H-Y, HPW/H-ZSM-5, HPW/USY, HPW/ReUSY, and HPW/SBA-15, were prepared using an impregnation method for alcoholysis of fructose to ethyl levulinate in ethanol. Among these catalysts, HPW/H-ZSM-5 showed the highest catalytic activity, and the yield of ethyl levulinate from fructose increased with i...

LaTonia Belcher and Sarah Teren under the supervision of: John Regalbuto and Marc Schreier Department of Chemical Engineering University of Illinois at Chicago ______________________________________________________________________ ABSTRACT: Currently the procedure on how to make over exchanged Cu-ZSM-5 is well known and can be made at many different exchange rates [1]. However, no one understan...

As stock of crude oil is limited, new resources for fuel and petrochemicals are required to be developed. Natural gas or biogas can be easily converted into methanol which can be converted into gasoline and olefins. This study uses zeolite catalyst (ZSM-5) and its modification by Ni to convert methanol to hydrocarbons (MTH). Catalysts are studied at different temperatures and at different loadi...

A continuous microwave equipment (CME) has been successfully developed in order to achieve an extremely rapid and mass production for ZSM-5 and NaY zeolite. A precursor mixture for synthesis of ZSM-5 was prepared by mixing aluminosilicate gel with a nanoseed solution obtained under microwave irradiation, and pumped continuously into the CME. Duration time in the CME was 5 min to accomplish the ...

The absorption of carbon monoxide with H-ZSM-5 and metal-substituted Li-ZSM-5 zeolites has been investigated by Ž . using both cluster and embedded cluster approaches at the HFr6–31G d,p level of theory. For the H-ZSM-5 zeolite, the binding energy of CO on a 3T quantum cluster is predicted to be 2.25 kcalrmol for the C-bound complex. The O-bound complex was found to be less stable by about 0.84...

Adsorption of carbonmonoxide on the silver ion-exchanged Ag-ZSM-5 zeolite has been studied using both quantum cluster and embedded cluster at the models B3LYP/6-31G(d,p) level of theory. The Ag...Oz distance in Ag-ZSM-5 complexes is predicted to be 2.26 Å for the quantum cluster and 2.32 Å for the embedded cluster, the latter is in agreement with the experimental value of 2.30 + 0.03 Å. The opt...

Hierarchical ZSM-5 zeolite is hydrothermally synthesized in a single step with cetyltrimethylammonium (CTA) hydroxide acting as mesoporogen and structure-directing agent. Essential to this synthesis is the replacement of NaOH with KOH. An in-depth solid-state NMR study reveals that, after early electrostatic interaction between condensed silica and the head group of CTA, ZSM-5 crystallizes arou...