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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. и др.
в: Journal of Structural Chemistry, Том 60, № 10, 01.10.2019, стр. 1599-1611.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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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.
N1 - Publisher Copyright: © 2019, Pleiades Publishing, Ltd.
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