scholarly journals Oxidative Degradation of Trichloroethylene over Fe2O3-doped Mayenite: Chlorine Poisoning Mitigation and Improved Catalytic Performance

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 747 ◽  
Author(s):  
Raffaele Cucciniello ◽  
Adriano Intiso ◽  
Tiziana Siciliano ◽  
Antonio Eduardo Palomares ◽  
Joaquín Martínez-Triguero ◽  
...  

Mayenite was recently successfully employed as an active catalyst for trichloroethylene (TCE) oxidation. It was effective in promoting the conversion of TCE in less harmful products (CO2 and HCl) with high activity and selectivity. However, there is a potential limitation to the use of mayenite in the industrial degradation of chlorinated compounds—its limited operating lifespan owing to chlorine poisoning of the catalyst. To overcome this problem, in this work, mayenite-based catalysts loaded with iron (Fe/mayenite) were prepared and tested for TCE oxidation in a gaseous phase. The catalysts were characterized using different physico-chemical techniques, including XRD, ICP, N2-sorption (BET), H2-TPR analysis, SEM-EDX, XPS FESEM-EDS, and Raman. Fe/mayenite was found to be more active and stable than the pure material for TCE oxidation, maintaining the same selectivity. This result was interpreted as the synergistic effect of the metal and the oxo-anionic species present in the mayenite framework, thus promoting TCE oxidation, while avoiding catalyst deactivation.

2017 ◽  
Vol 2 (5) ◽  
pp. 1812-1819 ◽  
Author(s):  
Daniele Costenaro ◽  
Chiara Bisio ◽  
Fabio Carniato ◽  
Sergey L. Safronyuk ◽  
Tatyana V. Kramar ◽  
...  

2014 ◽  
Vol 692 ◽  
pp. 240-244
Author(s):  
Gong De Wu ◽  
Xiao Li Wang ◽  
Zhi Li Zhai

A series of transition metal alanine-salicylaldehyde Schiff base chromium (III) complexes immobilized on MCM-41 were prepared and characterized by various physico-chemical measurements such as FIIR, XRD, HRTEM, N2 sorption and elemental analysis. The immobilized complexes were effective and stable catalysts for the epoxidation of styrene and cyclohexene with 30% hydrogen peroxide. Moreover, the metal centers were found to play important roles in the catalytic performance of immobilized complex catalysts.


2016 ◽  
Vol 6 (2) ◽  
pp. 363-378 ◽  
Author(s):  
C. H. Collett ◽  
J. McGregor

Carbonaceous deposits on heterogeneous catalysts are traditionally associated with catalyst deactivation. However, they can play a beneficial role in many catalytic processes, e.g. dehydrogenation, hydrogenation, alkylation, isomerisation, Fischer–Tropsch, MTO etc. This review highlights the role and mechanism by which coke deposits can enhance catalytic performance.


2022 ◽  
Vol 573 ◽  
pp. 151430
Author(s):  
Jiabin Dan ◽  
Pinhua Rao ◽  
Qiongfang Wang ◽  
Min Zhang ◽  
Zedi He ◽  
...  

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 530 ◽  
Author(s):  
Chaoqun Bian ◽  
Xiao Wang ◽  
Lan Yu ◽  
Fen Zhang ◽  
Jie Zhang ◽  
...  

The incorporation of metal heteroatoms into zeolites is an effective modification strategy for enhancing their catalytic performance. Herein, for the first time we report a generalized methodology for inserting metal heteroatoms (such as Sn, Fe, Zn, and Co) into the layered zeolite precursor RUB-36 via interlayer expansion by using the corresponding metal acetylacetate salt. Through this generalized methodology, Sn-JHP-1, Fe-JHP-1, Zn-JHP-1 and Co-JHP-1 zeolites could be successfully prepared by the reaction of RUB-36 and corresponding metal acetylacetate salt at 180 °C for 24 h in the presence of HCl solution. As a typical example, Sn-JHP-1 and calcined Sn-JHP-1 (Sn-JHP-2) zeolite is well characterized by the X-ray diffraction (XRD), diffuse reflectance ultraviolet-visible (UV-Vis), inductively coupled plasma (ICP), N2 sorption, temperature-programmed-desorption of ammonia (NH3-TPD) and X-ray photoelectron spectroscopy (XPS) techniques, which confirm the expansion of adjacent interlayers and thus the incorporation of isolated Sn sites within the zeolite structure. Notably, the obtained Sn-JHP-2 zeolite sample shows enhanced catalytic performance in the conversion of glucose to levulinic acid (LA) reaction.


2020 ◽  
Vol 44 (42) ◽  
pp. 18457-18468
Author(s):  
Maryam Arsalanfar

The effect of various preparation parameters on the catalytic performance and physico-chemical properties of a supported Fe–Mn catalyst was investigated using the RSM method.


Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1462
Author(s):  
Sichen Liu ◽  
Javier A. Otero ◽  
Maria Martin-Martinez ◽  
Daniel Rodriguez-Franco ◽  
Juan J. Rodriguez ◽  
...  

Chloromethanes are a group of volatile organic compounds that are harmful to the environment and human health. Abundant studies have verified that hydrodechlorination might be an effective treatment to remove these chlorinated pollutants. The most outstanding advantages of this technique are the moderate operating conditions used and the possibility of obtaining less hazardous valuable products. This review presents a global analysis of experimental and theoretical studies regarding the hydrodechlorination of chloromethanes. The catalysts used and their synthesis methods are summarized. Their physicochemical properties are analyzed in order to deeply understand their influence on the catalytic performance. Moreover, the main causes of the catalyst deactivation are explained, and prevention and regeneration methods are suggested. The reaction systems used and the effect of the operating conditions on the catalytic activity are also analyzed. Besides, the mechanisms and kinetics of the process at the atomic level are reviewed. Finally, a new perspective for the upgrading of chloromethanes, via hydrodechlorination, to valuable hydrocarbons for industry, such as light olefins, is discussed.


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