Improved performance of naphtha reforming process by the use of metal zeolite composite catalysts

Author(s):  
Jorge Beltramini ◽  
Akshat Tanksale
2020 ◽  
Vol 6 (2) ◽  
pp. 31
Author(s):  
Roba Saab ◽  
Kyriaki Polychronopoulou ◽  
Nikolaos Charisiou ◽  
Maria A. Goula ◽  
Andreas Schiffer

This paper examines the effect of incorporating graphene nanoplatelets (GNPs) in an Ni-based/Zeolite-Y catalyst on the hydrocracking of heptane fuel at two temperatures, 350 and 400 °C. Specifically, reduced GNP/NiO-ZY and NiO-ZY catalysts, each with a 5 wt. % Ni loading, were compared in this study. The results show that the reduced GNP/NiO-ZY enhanced the conversion percentage by 31% at 350 °C and by 6% at 400 °C as compared with the reduced NiO-ZY, and the GNP/NiO-ZY also showed superior stability, reporting a less than 2% drop in conversion over 20 h of time-on-stream. The enhancement in performance is linked to the surface and texture characteristics of both catalysts. Although the calcined GNP/NiO-ZY possessed a lower Brunauer–Emmett–Teller (BET) surface area of 458 m2/g compared with 536 m2/g for the calcined NiO-ZY, it showed a more hydrophobic nature, as deduced from the water adsorption profiles, which corroborates the hypothesis that the increased affinity between the catalyst surface and heptane molecules during the reaction leads to an improved catalytic activity.


2019 ◽  
Vol 9 (9) ◽  
pp. 1773 ◽  
Author(s):  
Yixiao Li ◽  
Quanhua Wang ◽  
Ding Wang ◽  
Xiaoliang Yan

Selective catalytic reduction of NO with methane (NO-CH4-SCR) in the presence of excess oxygen was investigated over the synthesized MnH-ZZs-n zeolite composite catalysts with FAU (as core) and BEA (as shell) topologies. XRD, SEM, and NH3-TPD technologies were employed to characterize the catalysts. It is found that the topological structure of the zeolite affected the catalytic properties and H2O/SO2 tolerances considerably. MnH-ZZs-n catalysts exhibited much higher NO-CH4-SCR activity than the physical mixture catalysts with comparable relative mass content of Y and Beta zeolites, particularly the ratio of Y and Beta at the range of 0.2–0.5 than the MnH-Beta catalysts with single topology. NH3-TPD results showed that one new type of strong acidic sites formed in H-ZZs-n and remained in MnH-ZZs-n resulted from the interaction between the Lewis and Brönsted acid sites under a particular environment. The special zeolite-zeolite structure with ion-exchanged Mn ions in the core-shell zeolite composite catalysts contributed to the novel NO-CH4-SCR properties.


Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1403
Author(s):  
Chi Zhou ◽  
Wencheng Liu ◽  
Hanqing Li ◽  
Miao Yang ◽  
Zixin Yang

Well-designed composite catalysts are of increasing concern due to their improved performance compared to individual components. Herein, we designed and synthesized an Fe3O4@MoS2 composite via a simple hydrothermal method. As for the resultant composite, the MoS2 nanolayers presented a novel piezo-catalytic effect, while the Fe3O4 core provided a magnetic separation property. The structure and properties of Fe3O4@MoS2 were determined by relevant experiments. It was found that Fe3O4@MoS2 exhibited enhanced piezo-catalytic degradation of rhodamine B and good magnetic recovery/recycling features. The kobs for rhodamine B degradation over Fe3O4@MoS2 was 0.019 min−1—a little longer than that over MoS2 (0.013 min−1). Moreover, Fe3O4@MoS2 also showed a favorable ability to adsorb rhodamine B in solution, with a saturation adsorption of 26.8 mg/g. Further studies revealed that piezo-electrons, holes, and superoxide anions were key species in the piezo-catalytic degradation of rhodamine B. Notably, the step where oxygen trapped electrons to produce superoxide anions had a significant impact on the degradation of the dye. This work, not limited to the development of a high-performance MoS2-based piezo-catalyst, is expected to provide new insights into the working mechanisms and process profiles of composite piezo-catalysts.


NANO ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. 1850117
Author(s):  
Yuan Zhao ◽  
JingXiu Li ◽  
Ling Wang ◽  
Yanan Hao ◽  
Lin Yang ◽  
...  

Sulfated TiO2 nanoparticles were successfully immobilized on zeolite through improving hydrolysis-deposition method. Microstructure, crystallization, surface state and surface area of composite catalysts were characterized by SEM, XRD, FTIR spectra, XPS and BET and the photocatalytic activity was evaluated by degradation of methyl orange under UV irradiation. We optimized these factors (SO[Formula: see text] ions, calcination temperature and loading amount of sulfated TiO[Formula: see text] on photocatalytic activity and crystallization of composite photocatalysts. The results indicated that the SO[Formula: see text] ions are successfully immobilized on the surface of TiO2, and sulfated TiO2/zeolite show the highest photocatalytic activity for methyl orange at the [SO[Formula: see text]]/[Ti[Formula: see text]] molar rate of 1:1, calcination temperature of 600[Formula: see text]C for 2[Formula: see text]h, and sulfated TiO2 loading amount of 40%, respectively.


2009 ◽  
Vol 130 (3-4) ◽  
pp. 308-311 ◽  
Author(s):  
Yanyan Xiao ◽  
Xinjun Li ◽  
Zhenhong Yuan ◽  
Juan Li ◽  
Yong Chen

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