On the catalytic role of superficial VOx species and coke deposited on mesoporous MgO replica in oxidative dehydrogenation of ethylbenzene
| Autor: | Carlos Cuadrado-Collados, Sebastian Jarczewski, Jesus Gandara-Loe, Lidia Lityńska-Dobrzyńska, Joaquín Silvestre-Albero, Piotr Kuśtrowski, Piotr Michorczyk, Marek Drozdek |
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| Přispěvatelé: | Universidad de Alicante. Departamento de Química Inorgánica, Universidad de Alicante. Instituto Universitario de Materiales, Materiales Avanzados |
| Rok vydání: | 2020 |
| Předmět: |
Coke deposition
General Physics and Astronomy Vanadium chemistry.chemical_element 02 engineering and technology 010402 general chemistry 01 natural sciences Ethylbenzene Catalysis Styrene chemistry.chemical_compound Ammonium metavanadate Regeneration Dehydrogenation Magnesium vanadate Nanoreplication Química Inorgánica Chemistry Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Surfaces Coatings and Films Magnesium nitrate Chemical engineering 0210 nano-technology Mesoporous material Styrene production Oxidative dehydrogenation |
| Zdroj: | RUA. Repositorio Institucional de la Universidad de Alicante Universidad de Alicante (UA) |
| Popis: | Mesoporous MgO was synthesized by the nanoreplication method using CMK-3 carbon as a hard template and magnesium nitrate as a metal oxide precursor. The produced support was modified with different amounts of ammonium metavanadate solution. Various distributions of V-containing species on the MgO surface were found by XRD, low-temperature adsorption of N2, TEM, XPS and UV–vis-DR spectroscopy. At low V loadings isolated VO4 dominated. Increasing V content resulted in clustering of VO4 species and the formation of Mg3V2O8 crystallites. As found in temperature-programmed reduction (H2-TPR), the latter phase was clearly harder in reduction by H2 compared to highly dispersed VO4 forms. The developed materials appeared to be very active catalysts of oxidative dehydrogenation of ethylbenzene (ODH). The optimal catalytic performance was observed for the sample containing 10 wt% of vanadium. The initial ethylbenzene conversion of 63.6% at selectivity to styrene of 86.9% was achieved at temperature as low as 500 °C. A notable influence of carbonaceous deposit formed during the ODH reaction on the catalytic activity was discussed, including presentation of both coexisting superficial reaction mechanisms. A reasonable regeneration procedure to recover lost activity was developed. This work was supported by the Polish National Science Centre (grant no. 2013/09/B/ST5/03419). The research was carried out with the equipment purchased thanks to the financial support of the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (contract no. POIG.02.01.00-12-023/08). S.J. received a doctoral scholarship from the Polish National Science Centre (grant no. 2016/20/T/ST5/00256). J.S.A. acknowledges financial support by MINECO (Project MAT2016-80285-p), H2020 (MSCA-RISE-2016/NanoMed Project), and GV (PROMETEOII/2014/004). |
| Databáze: | OpenAIRE |
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