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Synthesis and characterization of TiO2/ZSM-5 photocatalysts for degradation of rhodamine

Liu Rulai, Hu Jiapeng, Rau Juiye, Lin Hao, He Huan, Gao Biao, Lai Wenliang

Environment Protection Engineering

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2022

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Vol. 48, nr 2

29--42

EN

ZSM-5 synthesized by the hydrothermal method from raw kaolin clay was used as support to prepare TiO2/ZSM-5 catalysts via the sol-gel method. All prepared samples were characterized by X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), ultraviolet-visible spectroscopy (UV-Vis), transmission electron microscopy (TEM), particle size analysis and surface area measurement. The photocatalytic performance of TiO2/ZSM-5 was investigated based on rhodamine B (RhB) removal under UV radiation (450-600 nm. The results showed that the kaolin clay was successfully transformed into ZSM-5. The BET surface area and pore size distribution of the synthesized ZSM-5 were 364 m2/g and 0.54 nm, respectively. SEM and TEM revealed that TiO2 nanoparticles were well distributed on the surface of ZSM-5. The composite TiO2/ZSM-5 catalyst showed 98.53% removal, which is higher than that of pure TiO2 (80.13%) due to adsorption and degradation of RhB (5.0 mg/dm3) under 60 min UV light irradiation at 1 g/dm3 photocatalyst loading. The synergistic effect of TiO2 and ZSM-5, including adsorption, conduction band electron (e-), and valence-band holes (h+), makes the composite superior to pure TiO2, showing its potential for the degradation of organic dye.

2

Catalytic pyrolysis of metal free PCBs with ZSM-5 and Ca(OH)2

Pandere Vaibhav, Gautam Alok, Gautam Shina

Chemical and Process Engineering

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2022

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Vol. 43, nr 2

171-–182

EN

Presence of heavier molecules and toxic brominated compounds in pyrolysis products of printed circuit boards (PCB) make their use difficult. In the present work to overcome this problem PCBs were pyrolyzed in presence of catalysts such as ZSM-5 and Ca(OH)2 to study their effect on pyrolysis products. The comparison of non-catalytic pyrolysis of PCB was done with oil and gas compositions produced by both techniques. Pyrolysis experiments were done at a lab scale set-up. However, the increased concentrations of ZSM-5 were found to increase char and gases were found to be rich in CH4 and O2. The composition of oils was mainly composed of phenols, phenol derivatives and aromatic compounds, which increased with pyrolysis with ZSM-5 and Ca(OH)2. Ca(OH)2 was found effective in removing brominated compounds from oil and no halogens were observed in oil. Char produced during pyrolysis was mesoporous in nature and composed of some fractions of metals and glass fibers.

3

Effect of boron on ZSM-5 catalyst for methanol to propylene conversion

Xu A., Ma H., Zhang H., Ying W., Fang D.

Polish Journal of Chemical Technology

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2013

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Vol. 15, nr 4

95-101

EN

B-ZSM-5 catalysts were prepared by various modification methods with boric acid, including ion-exchange, impregnation and direct synthesis. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), NH3-Temperature Programmed Desorption (NH3-TPD), N2 adsorption-desorption, Fourier Transform Infrared spectrometry (FT-IR), 27Al and 11B MAS NMR spectra. The results revealed that the weak acidity of catalysts was significantly increased by modification. The catalytic activity was measured in a fixed bed at 460°C for methanol to propylene (MTP) reaction. The results of MTP reaction showed a great increment of the propylene selectivity for the boron modified samples, especially for the directly synthesized B-ZSM-5 which also displayed high activity and selectivity towards C2 =-C4 = olefins. It was found that the remarkable selectivity strongly depended on the intensity of weak acidity.

4

Density Functional Calculations on the Adsorption of N2O and H2O on the Ion-ex changed ZSM-5

Gao H. W., Guo L., Deng H. H., Ge L. Y., Yan T. X.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 6

1195-1201

EN

Density functional theory (DFT) calculations were performed to study the configuration and electronic states of N2O and H2O adsorbed on the ion-ex changed ZSM-5 using the Gaussian98 program. We also calculated the adsorption energy of NO2 species and H2O ad sorbed on various ion exchanged ZSM-5. The calculated results indicated that Cu+, Co2+ and Ti3+ sites on ZSM-5 have strong affinity to N2O and these metal cations are stable against water poisoning.

5

Influence of heteropoly acid and USY zeolite on activity of ZSM-5 containing catalysts.

Grzechowiak J. R., Masalska A.

Prace Naukowe Instytutu Chemii i Technologii Nafty i Węgla Politechniki Wrocławskiej. Konferencje

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2002

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Vol. 10, nr 57

343-348

EN

Activity and selectivity of Ni/ZSM-5+Al2O3 catalyst (8 wt.% NiO) containing 30 wt.% Ni,H-ZSM-5 were compared to those of catalysts to which USY zeolite, Ni,H-ZSM-5 zeolite, and heteropoly acid were added (20%). The ZSM-5 containing catalyst modified with heteropoly acid was less active than those modified by zeolite (USY, ZSM-5). N-Hexane conversion was highest for the catalyst contg. 50 wt.% zeolite. The yield of hydrocracking products was higher for the catalyst contg. 50 wt.% ZSM-5 than that of catalyst containing 30 wt.% ZSM-5 and 20 wt.% USY zeolites. Modification of the ZSM-5 containing catalyst did not result in higher yield of isomerization products.