Sciact
  • EN
  • RU

The Evolution of the M1 Local Structure during Preparation of VMoNbTeO Catalysts for Ethane Oxidative Dehydrogenation to Ethylene Full article

Journal RSC Advances
ISSN: 2046-2069
Output data Year: 2018, Volume: 8, Number: 63, Pages: 35903-35916 Pages count : 14 DOI: 10.1039/c8ra06424e
Tags Catalyst selectivity; Crystal structure; Dehydrogenation; Distribution functions; Ethane; Ethylene; Hydration; Tellurium compounds
Authors Kardash T.Yu. 1 , Lazareva E.V. 1 , Svintsitskiy D.A. 1 , Ishchenko A.V. 1 , Bondareva V.M. 1 , Neder R.B. 2
Affiliations
1 Boreskov Institute of Catalysis SB RAS, Pr. Ak. Lavrentieva, 5, Novosibirsk, Russia
2 Friedrich-Alexander University of Erlangen-Nuremberg, Staudtstr. 3., 91058 Erlangen, Germany

Funding (1)

1 Russian Science Foundation 17-73-20073

Abstract: The so-called M1 phase (the common formula (TeO)x(Mo, V, Nb)5O14) is a very promising catalyst for ethane oxidative dehydrogenation (ODE). It shows 90% selectivity to ethylene at 78% ethane conversion (400 °C, contact time – 5.5 s). The active crystal structure is formed under certain synthetic conditions in VMoNbTe mixed oxides. This paper is devoted to the analysis of how the local and average structure of the M1 phase is developed during the synthesis and what happens at particular synthetic steps. The analysis of the local structure was performed using the EXAFS and pair distribution function (PDF) methods. The EXAFS analysis of the initial VMoTe water solution and VMoNbTe slurry showed that Anderson-type heteropoly anions are formed in the solution and are preserved after fast spray-drying of the slurry. Nb cations do not enter the structure of the polyanions, but form an extended hydrated oxide matrix, where distorted NbO6 and NbO7 polyhedrons are connected to each other. The hydrated oxide matrix with captured polyanions provides the compositional homogeneity of the precursor. The distances in the second coordination shell are redistributed after thermal treatment at 310 °C. After being heated at T > 350°, the local structure of the M1 phase is organized and pentagonal domains are formed. These domains consist of a NbO7 pentagonal bipyramid and five MeO6 adjacent octahedra (Me = Mo, V). In the first stages, the building blocks are stacked along the [001] direction. The crystallization process results in the connection of the pentagonal domains to the extended polygonal grid. The formation of the regular grid with TeOx containing channels is accompanied by the increase in ethane conversion and ethylene selectivity of the catalysts.
Cite: Kardash T.Y. , Lazareva E.V. , Svintsitskiy D.A. , Ishchenko A.V. , Bondareva V.M. , Neder R.B.
The Evolution of the M1 Local Structure during Preparation of VMoNbTeO Catalysts for Ethane Oxidative Dehydrogenation to Ethylene
RSC Advances. 2018. V.8. N63. P.35903-35916. DOI: 10.1039/c8ra06424e WOS Scopus РИНЦ AN PMID OpenAlex
Files: Full text from publisher
Dates:
Submitted: Jul 30, 2018
Accepted: Oct 11, 2018
Published online: Oct 22, 2018
Identifiers:
Web of science: WOS:000448663500006
Scopus: 2-s2.0-85056088522
Elibrary: 38663170
Chemical Abstracts: 2018:1961311
PMID: 35558492
OpenAlex: W2896842647
Citing:
DB Citing
Web of science 29
Scopus 31
Elibrary 28
OpenAlex 32
Altmetrics: