Papers by Keyword: ZSM-5

Abstract: Morphology of silver nanoparticle coated on ZSM-5, mordenite, and Y-Type zeolite by Stöber’s and Tollen’s methods was characterized. The silver element was confirmed by SEM, EDX spectrum and XRD. Nanoparticle size of the silver fabricated on the surface of all three types of zeolite by Stöber’s method appeared in 1.8-7.9 times smaller than the Tollen’s methods depending on the Si/Al ratio of the zeolite. The ZSM-5, containing the highest Si/Al ratio and the largest crystal size, provided the best adhesion to the silver nanoparticles. Analysis of the SEM image showed a well distribution of silver nanoparticles on all types of zeolites, but only for the Stöber’s coating technique. A 4.54% coverage area of the silver nanoparticles on the Y-Type zeolite was enough for transformation the crystalline structure of zeolite surface to amorphous as consequent of the broad peak XRD spectrum. Since the zeolite surface was not fully obscured by silver nanoparticles as confirmed by FTIR, its absorption property of zeolite was also preserved. The Raman signal enhancement was evident when zeolite was coated with silver nanoparticle.

Abstract: ZSM-5 has been successfully synthesized by seeding method using coal bottom ash and rice husk as the sources of silica and alumina.Synthesis ZSM-5 were performed by the hydrothermal method in autoclave autogenous at 180 °C for 36 h with molar ratio 10Na : 50SiO : 2Al2O3 : 500H2O with the addition of ZSM-5 commercial as seed. In this experiments, investigated variations seed amounts of 5, 10, 15, and 20% of weight silica. The product was characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), and Brunauer-Emmet-Teller (BET). Resulted showed that ZSM-5 succeed formed in all variation of seed contain. At variation seed amount 5%, crystallinity obtained still low in which content of quartz phase still be high. Percent crystallinity highest obtained at the variation of seed amount 20% with the result percent crystallinity relative 106%. The experimental results revealed that phase transformation has occurred, in which an amorphous phase of coal bottom ash and rice husk has been transformed to the ZSM-5 crystal with addition seed as substitution organic template.

Abstract: A series of hierarchical HZSM-5 catalysts were synthesized by alkaline (denoted as HZSM-5-At) and/or alkaline-acid (denoted as HZSM-5-At-acid) treatments, and they as catalyst pairs were employed for the synthesis of glycerol and ammonia toward pyridine bases in a series-connected two-stage reactor. The characterization was analysed by means of N₂-physorption and NH₃-TPD techniques. The catalytic evaluation showed that the lower Si/Al ratio (Si/Al = 25 before treatment) in catalyst pairs (HZSM-5-At + ZnO/HZSM-5-At-acid) possessed the highest total yield of pyridine bases among all the catalyst pairs, but the suitable Si/Al ratio in alkaline-treated ZSM-5 (Si/Al = 38 before treatment) in the first stage of reactor and ZnO/HZSM-5-At-acid (Si/Al = 25 before treatment) in the second stage of reactor had the stronger stability relative to other catalyst pairs. The characterization revealed that the amount of acid sites play a vital role in the formation of pyridine bases whereas the appearance of mesoporous structure and the declined concentration of acid sites were main reasons for promoting the stability.

Abstract: A series of zeolite-derived silica glasses have been fabricated through the order-disorder transition process of zeolites using spark plasma sintering (SPS). The samples were characterized by UV-VIS-NIR transmittance, Raman spectra and Vicker’s hardness. Results showed that the transmittance of zeolite-derived silica glass samples increased with the sintering temperature increasing. The transmittance of the sample prepared at 1300°C was lower than 5%. The highly transparent samples could be obtained when the sintering temperature was above 1350°C. The transmittance of these samples was higher than 80% in the range of 780~1700nm and 60% in the UV-vis range of 250~780nm. One absorption band at 300nm can also be observed in the spectrum. The reason of this phenomenon could be ascribed to a few left crystallite fragments of ZSM-5. The Raman spectra showed that the bands at 378 and 292cm^-1of ZSM-5 were significantly weakened and then disappeared with increasing the sintering temperature and the bands at 489 and 600cm^-1 of silica glass became more apparent. The Raman spectra of the samples obtained above 1350°C were the same as that of the fused silica glass. The Vicker’s hardness of as-prepared samples increased with the rising of the sintering temperature. The maximum hardness of 7.31 GPa was achieved for the sample sintered at 1400°C. The fracture toughness of samples increased from 0.83 MPa·m^1/2 to 2.37 MPa·m^1/2 with the sintering temperature increasing.

Abstract: The effects of calcinations temperature toward physical properties of ZSM-5 were determined by treatment with different temperature for 24 hour. The main properties of these samples were characterized by means of XRD, FTIR, BET surface area measurement and TGA. The hydrothermal treatments were carried out at various temperature of 200°C-500°C. The content in the natural granite sample were also performed .Throughtout this experiment, from the XRD and FTIR analysis the natural granite samples shows the existing of zeolite component which is SiO₂ and aluminium oxide.

Abstract: ZSM-5 zeolite was synthesized via a template-free method. The influence of crystallization time was investigated. The obtained samples were characterized by XRD, SEM and FTIR. Results shown that with the ratio of 8 Na₂O : 80 SiO₂ : 2 Al₂O₃ : 2500 H₂O, the crystallization for ZSM-5 began at ca. 9 h. And fine ZSM-5 zeolite (ca. 10~15 μm) could be obtained by crystallizing at 190 °C for 10 h. Further increasing time would lead to the appearance of quartz.

Abstract: TiO₂ and ZnO were incorporated into ZSM-5 using titanium tetrachloride and zinc nitrate as the precursors respectively. The functional group of ZSM-5 was further modified using mercaptopropyl trimethoxysilane (MPTS). This method was used to produce a two-in-one composite namely TiO₂-ZSM5-SH and ZnO-ZSM5-SH which holds the abilities to degrade organic pollutants as well as to remove them from the environment. Determination of the composition and morphology of all synthesized catalyst complexes were characterized using Fourier Transformed Infrared (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HR-TEM). Results obtained indicated that the average diameters for TiO₂-ZSM5-SH particles are 2.398 μm, slightly larger than the diameter of ZnO-ZSM5-SH particles with an average of 1.8067 μm. Both TiO₂-ZSM5-SH and ZnO-ZSM5-SH appeared as sphere-like shape and amorphous since both metal oxides were incorporated into the ZSM-5 pores. The compositions of these complexes were proven by the presence of a strong silica absorption band showing the existence of Si-O stretching vibrations and SiO₂ asymmetric vibrations in the synthesized complexes. For TiO₂-ZSM5-SH, the Ti-O stretching vibration can be seen at 3467.29 cm^-1 and at 1637.86 cm^-1 while Zn-O absorption band appeared at 455.52 cm^-1 in ZnO-ZSM5-SH. The symmetric and asymmetric vibrations of –CH₂ and –CH₃ indicate the existence of alkyl groups in the ZSM-5. The ability of catalyst complexes synthesized as photocatalyst were applied and tested on the photodegradation of dimethylarsenic acid (DMA) under ultra violet (UV) radiation which showed that these catalyst complexes are proven be able to degrade DMA into less toxic intermediates and are able to adsorb the remaining arsenic species from the aqueous solutions.

Abstract: The anticorrosion performance of Al2024 deposited ZSM-5 zeolite membranes prepared by situ hydrothermal method is analyzed. The results of polarization curve show that the corrosion position of Al2024 deposited zeolite membranes was higher than blank samples and the samples position at 10 h was highest. The impandance rings of samples at 10 h was biggest and the corrosion charact was uniform corrosion different from pit corrosion of Al2024 without zeolite membranes.

Abstract: Bio-based butanol has superior properties when compared to ethanol to be the gasohol and is gradually considered to be an important biofuel from the biomass fermentation of ABE solution. The potential sorbents for acetone (A), 1-butanol (B), and ethanol (E) recovery process will be analyzed by the isotherm data and the sorbents, such as potato starch sorbent and ZSM-5 will be selected. The above sorbents to adsorb acetone, 1-butanol, and ethanol for single-component adsorption using adsorption equilibrium apparatus will be conducted and the isotherm data will be obtained.

Abstract: The objective of this work is to obtain synthesis of ZSM-5 zeolite using kaolin as Si and Al alternative source. Kaolin powder was dispersed under constant stirring into the sílica sol where the mass ratio of kaolin to silica was 1:2. After stirring for 2 hours, the dispersion was dried at 160 °C and calcined at 700 °C/2 hours. The synthesis of ZSM-5 zeolite was by hydrothermal treatment at 170 °C/48 hours under autogenous pressure. The materials were characterized by XRD, SEM, EDX, BET. According to the XRD, was possible to observe the formation of ZSM-5 zeolite with intense and well defined peaks set located between 2θ = 7-9° and 23-25°, typical of a crystalline material. The SEM showed the formation of particles clusters with orthorhombic shape characteristic of MFI structure. The results show that the hydrothermal treatment was efficient to produce ZSM-5 using calcined kaolin as alternative source.