Powder X-Ray Study Under In Situ Conditions of the Hydrogen Reduction of NiMoO4-SiO2
O.A. Bulavchenko1,2, A.A. Smirnov1, S.A. Khromova1,2, Z.S. Vinokurov1,2, A.V. Ishchenko1,2, V.A. Yakovlev1, S.V. Tsybulya1,2
1Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk National State Research University, Novosibirsk, Russia
Keywords: смешанные оксиды, in situ рентгенография, восстановление, mixed oxides, in situ powder X-ray diffraction, reduction
Abstract
Interest in the reduction of NiMoО4-SiO2 is related to its promising use as catalysts in hydrodeoxygenation and hydrodesulfurization processes. By means of in situ X-ray diffraction phase transformations occurring during the hydrogen reduction of NiMoO4-SiO2 in the temperature range 30-700 °C are studied in this work. It is shown that the reduction of a-NiMoО4 proceeds in two stages. At the first stage, at 400-500 °C an intermediate state forms, which is a mixed oxide (Ni,Mo,□)O and Ni1- x Mo x . At the second stage, above 650 °C, two solid solutions form based on Mo and Ni structures. By the Rietveld method the structure of the intermediate state is refined. It is shown that the mixed Ni-Mo oxide forms based on the NiO structure, which contains some amount of cation vacancies.
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