In situ Study of Structural Transformations of the Active Phase of VMoNbTeO Catalysts under Reduction Conditions

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In situ Study of Structural Transformations of the Active Phase of VMoNbTeO Catalysts under Reduction Conditions. / Kardash, T. Yu ; Marchuk, A. S.; Ishchenko, A. V. et al.

In: Journal of Structural Chemistry, Vol. 60, No. 10, 01.10.2019, p. 1599-1611.

Research output: Contribution to journal › Article › peer-review

BibTeX

@article{210d8d5293cb412c8d95fd42005b46f7,

title = "In situ Study of Structural Transformations of the Active Phase of VMoNbTeO Catalysts under Reduction Conditions",

abstract = "VMoNbTeO catalysts show high activity in the reactions of selective oxidation of ethane and propane. Time-resolved X-ray diffraction is used to study structural transformations of a mixed oxide with the composition (TeO)0.18(Mo0.7V0.22Nb0.08)20O56 and the structure of the active M1 phase upon heating in a hydrogen atmosphere (1% H2 in helium). It is shown that the structure of the M1 phase is destroyed in the presence of a reducing agent above 480 °C. The process is accompanied by structural distortions, diminishing of the size of crystalline blocks, elimination of tellurium (due to the reduction and sublimation), and the reduction by molybdenum and vanadium cations. As a result, VMoNb oxides with a disordered structure are formed and rapidly crystallized at T > 480 °C into the rutile-type monoclinic oxide (Mo,V,Nb)O2 with a variable composition. X-ray photoelectron spectroscopy and transmission electron microscopy data confirm heterogeneous compositions of oxides formed by the decomposition of the initial phase. The surface of the formed particles is enriched with vanadium and niobium present in the composition of the oxides with disordered structure.",

keywords = "M1 phase, VMoNbTeO catalysts, X-ray diffraction in situ, SELECTIVE OXIDATION, STATES, MOLYBDENUM, PERFORMANCE, STABILITY, PROPANE, HYDROTHERMAL SYNTHESIS, M1 MOVTENB OXIDE, SURFACE, OXIDATIVE DEHYDROGENATION",

author = "Kardash, {T. Yu} and Marchuk, {A. S.} and Ishchenko, {A. V.} and Simanenko, {A. A.} and Lazareva, {E. V.} and Svintsitskiy, {D. A.}",

note = "Publisher Copyright: {\textcopyright} 2019, Pleiades Publishing, Ltd.",

year = "2019",

month = oct,

day = "1",

doi = "10.1134/S0022476619100056",

language = "English",

volume = "60",

pages = "1599--1611",

journal = "Journal of Structural Chemistry",

issn = "0022-4766",

publisher = "Springer GmbH & Co, Auslieferungs-Gesellschaf",

number = "10",

}

RIS

TY - JOUR

T1 - In situ Study of Structural Transformations of the Active Phase of VMoNbTeO Catalysts under Reduction Conditions

AU - Kardash, T. Yu

AU - Marchuk, A. S.

AU - Ishchenko, A. V.

AU - Simanenko, A. A.

AU - Lazareva, E. V.

AU - Svintsitskiy, D. A.

PY - 2019/10/1

Y1 - 2019/10/1

N2 - VMoNbTeO catalysts show high activity in the reactions of selective oxidation of ethane and propane. Time-resolved X-ray diffraction is used to study structural transformations of a mixed oxide with the composition (TeO)0.18(Mo0.7V0.22Nb0.08)20O56 and the structure of the active M1 phase upon heating in a hydrogen atmosphere (1% H2 in helium). It is shown that the structure of the M1 phase is destroyed in the presence of a reducing agent above 480 °C. The process is accompanied by structural distortions, diminishing of the size of crystalline blocks, elimination of tellurium (due to the reduction and sublimation), and the reduction by molybdenum and vanadium cations. As a result, VMoNb oxides with a disordered structure are formed and rapidly crystallized at T > 480 °C into the rutile-type monoclinic oxide (Mo,V,Nb)O2 with a variable composition. X-ray photoelectron spectroscopy and transmission electron microscopy data confirm heterogeneous compositions of oxides formed by the decomposition of the initial phase. The surface of the formed particles is enriched with vanadium and niobium present in the composition of the oxides with disordered structure.

AB - VMoNbTeO catalysts show high activity in the reactions of selective oxidation of ethane and propane. Time-resolved X-ray diffraction is used to study structural transformations of a mixed oxide with the composition (TeO)0.18(Mo0.7V0.22Nb0.08)20O56 and the structure of the active M1 phase upon heating in a hydrogen atmosphere (1% H2 in helium). It is shown that the structure of the M1 phase is destroyed in the presence of a reducing agent above 480 °C. The process is accompanied by structural distortions, diminishing of the size of crystalline blocks, elimination of tellurium (due to the reduction and sublimation), and the reduction by molybdenum and vanadium cations. As a result, VMoNb oxides with a disordered structure are formed and rapidly crystallized at T > 480 °C into the rutile-type monoclinic oxide (Mo,V,Nb)O2 with a variable composition. X-ray photoelectron spectroscopy and transmission electron microscopy data confirm heterogeneous compositions of oxides formed by the decomposition of the initial phase. The surface of the formed particles is enriched with vanadium and niobium present in the composition of the oxides with disordered structure.

KW - M1 phase

KW - VMoNbTeO catalysts

KW - X-ray diffraction in situ

KW - SELECTIVE OXIDATION

KW - STATES

KW - MOLYBDENUM

KW - PERFORMANCE

KW - STABILITY

KW - PROPANE

KW - HYDROTHERMAL SYNTHESIS

KW - M1 MOVTENB OXIDE

KW - SURFACE

KW - OXIDATIVE DEHYDROGENATION

UR - http://www.scopus.com/inward/record.url?scp=85074637627&partnerID=8YFLogxK

U2 - 10.1134/S0022476619100056

DO - 10.1134/S0022476619100056

M3 - Article

AN - SCOPUS:85074637627

VL - 60

SP - 1599

EP - 1611

JO - Journal of Structural Chemistry

JF - Journal of Structural Chemistry

SN - 0022-4766

IS - 10

ER -

ID: 22333569