Under the applied reactions conditions, all the carbon-based materials are apparently stable in the first 15 h time on stream. This may be accomplished in many ways: improving the catalyst performance and durability by gaining insights in reaction, activation, and deactivation mechanisms; lowering the amount of critical or harmful catalytic components, e.g., by finding cheaper, more abundant, and sustainable substitutes; and making catalysts production and disposal processes more sustainable, e.g., by recycling. At 650 °C, the ethylbenzene conversion due to thermal cracking was significantly increased by the catalytic activity of the chars (from 37.2 up to 85.8%). Departamento de Física, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil, c PlasticsEurope would also like to thank these companies for their valuable contributions and peer review of this document: BASF SE INEOS Styrolution Europe GMBH LyondellBasell Repsol Química S.A. A mechanism is described indicating the role of the O2−–Fe 2019 Catalysis Science & Technology HOT Articles The stability was evaluated from runs of 60 h time on stream. There are more references available in the full text version of this article. Under the optimized reaction condition, the yield of benzaldehyde can achieve 78.9% with 96.8% styrene conversion and 81.5% benzaldehyde selectivity. This article is part of the themed collection: For reproduction of material from all other RSC journals and books: For reproduction of material from all other RSC journals. A rigorous heterogeneous model describing the behavior of a membrane reactor in which ethylbenzene was dehydrogenated to styrene, was developed by Abdalla and Elnashaie (1994). Since the reaction of ethylbenzene to styrene is endothermic, it is carried out in multiple adiabatic radial bed reactors filled with catalysts. Pyruvic acid and pyruvate derivatives are important chemical intermediates which are normally produced using metal-based catalytic materials that could cause serious environmental problems. The maximum CnOH-to-CnHO conversion of 97.2 and 99.9% with productivity of 63.2 and 65 mmol g−1 h−1 was achieved with 0.1 g of each Zn-Mn oxide and Zn-Mn oxide/FMWCNT, respectively in water at 60 °C and time = 120 min. Various characterization results show that the Co3O4@HZSM-5 catalyst has well-organized structure with Co3O4 particles compatibly encapsulated in the zeolite crystals. The catalytic efficiencies of the prepared catalysts were tested for liquid phase oxidation of cinnamyl alcohol (CnOH) to cinnamaldehyde (CnHO) in a modified batch reactor. The adsorption of ethylbenzene takes place preferentially in the outermost FeOx (x > 4) sites (Lewis acid) and the dehydrogenation reaction occurs predominantly in the oxygens bound to iron (Lewis base) according to the complementary electrostatic potential surface approach. The reaction proceeded through the direct route in which the intermediate nitrosobenzene was converted directly to aniline quickly. Please enable JavaScript The Co3O4@HZSM-5 catalyst was employed as an efficient catalyst for the selective oxidation of styrene to benzaldehyde with hydrogen peroxide as a green and economic oxidant. Comparison of the Behavior of Metal–Organic Frameworks and Zeolites for Hydrocarbon Separations. It is used to make rubbers, polymers and copolymers, and polystyrene plastics. The site requirements of the optimal catalyst to create the more selective coke is related to the higher density of Lewis sites per surface area, no mixed Si–Al Brønsted sites are formed while the acid strength of the formed Lewis sites is relatively weaker than those of the bare alumina. Chemical titration results provide direct evidence that ketonic carbonyl groups on nanocarbon are active sites for this reaction. Author information: (1)International Campus-Tehran University of Medical Sciences (IC-TUMS), Tehran, Iran. The reaction is found to be second order in ethylbenzene and zero order in oxygen with an activation energy of 76.5 kJ/mol. Such an excellent catalytic performance can be attributed to the synergistic effect between the confined reaction environment and the proper acidic property. The catalytic tests confirmed that the cobalt ferrite is more active and stable than the traditional hematite catalyst. Toluene and benzene are formed by (1) dealkylation reaction, (2) hydrodealkylation reaction and (3) steam dealkylation. TGA, TPD, TEM, N2 adsorption-desorption, and Raman spectroscopy were used to show that it was oxygenated groups that gave catalytic activity, while the surface area, pore structure, morphology, structural defects and Fe impurities in the catalysts did not have a significant influence on the activity. Special attention was given to the reaction conditions, using a relatively concentrated EB feed (10 vol.% EB), and limited excess of O2 (O2:EB = 0.6) in order to work at full oxygen conversion and consequently avoid O2 in the downstream processing and recycle streams. Relevant carbon-based materials, home-made carbon–silica hybrids, commercial activated carbon, and nanostructured multi-walled carbon nanotubes (MWCNT) were tested in the oxidative dehydrogenation of ethylbenzene (EB). As a valuable source material, styrene itself is produced from ethylbenzene, usually by dehydrogenation using steam over an iron oxide catalyst, 1-3 or equally can be produced by the reduction of phenylacetylene using hydrogen gas over a Lindlar catalyst. We use cookies to help provide and enhance our service and tailor content and ads. were temperature = 620oC, steam to ethylbenzene mole ratio = 11, and partial pressure of N2 diluent = 0.432 bar. Two types of catalyst families have been proven to be active and selective for EB ODH.Inorganic-based materials such as aluminas [3–8], metal pyrophosphates [9–11], and phosphates [10–20] or P-supported silica [10,21] have been reported as a first class of catalysts.There is a general consensus that the coke deposit generated on the acid sites under these oxidative reaction conditions is more active and selective for the production of ST than the inorganic material itself [3–6,8,22]. 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