Nanodispersed Zn—MoO3 catalysts of selective ethanol oxidation synthesized by nontraditional methods

Sachuk, OV
Dopov. Nac. akad. nauk Ukr. 2019, 6:48-53
https://doi.org/10.15407/dopovidi2019.06.048
Section: Chemistry
Language: Ukrainian
Abstract: 

The main features of transformations in the oxide ZnO—MoO3 = 1 : 1 composition under the action of ultrasonic (UST) and mechanochemical (MChT) treatments are established. The studies of modified samples demonstrate changes in the crystal structure of oxides, morphology of their surface, porous structure, and particle size (up to 13 nm), which stimulate the formation of new compounds directly in the processes of MCh and US treatments. The possibility of a simple formation of nanodispersed α- and β-phases of zinc molybdate ZnMoO4 in the form of needles and rods under the ultrasonic and mechanochemical activation, respectively, and the effectiveness of using these nontraditional methods to obtain highly active and selective zinc-molybdenum catalysts are shown. The high catalytic activity of the synthesized samples in the reaction of selective oxidation of ethanol to acetic aldehyde at 205 °C with a maximum yield of 94-96 % for this product is established.

Keywords: ace tic aldehyde, ethanol, nanodispersed composition, ultrasonic and mechanochemical treatments, zinc molybdate
References: 

1. Jørgensen, B., Kristensen, S. B., Kunev-Kruse, A. J., Fehrmann, R., Christensen, C. H. & Riisager, A. (2009). Gas-phases oxidation of aqueous ethanol by nanoparticle vanadia/anatase catalysts. Top. catal., 52, Iss. 3, pp. 253-257. doi: https://doi.org/10.1007/s11244-008-9161-5
2. Yoshitake, H., Aoki, Y. & Hemmi, S. (2006). Mesoporous titania supported-molybdenum catalyst: The formation of a new mesophase and use in ethanol-oxygen catalytic reactions. Micropor. Mesopor. Mat., 93, Iss. 1-3, pp. 294-303. doi: https://doi.org/10.1016/j.micromeso.2006.03.008
3. Li, M., Wu, Z. & Overbury, S. H. (2013). Surface structure dependence of selective oxidation of ethanol on faceted CeO2 nanocrystals. J. Catal., 306, pp. 164-176. doi: https://doi.org/10.1016/j.jcat.2013.06.019
4. Gonçalves, F. M., Medeiros, P. R. S. & Appel, L. G. (2001). The role of cerium in the oxidation of ethanol over SnO2-supported molybdenum oxides. Appl. Catal. A. Gen., 208, No. 1-2, pp. 265-270. doi: https://doi.org/10.1016/S0926-860X(00)00716-X
5. Pat. 116067 UA, IPC С01G 39/02, C01G 9/02, Mechanochemical method of obtaining nanosized rods β-ZnMoO4, Sachuk, O.V., Zazhigalov, V.A., Publ. 10.05.2017 (in Ukrainian).
6. Pat. 117264 UA, IPC С01G 39/02, C01G 9/02, Sonochemical method for obtaining a nanosized phase α-ZnMoO4, Sachuk, O.V., Zazhigalov, V.A., Starchevskyy, V.L., Publ. 26.06.2017 (in Ukrainian).
7. Keereeta, Y., Thongtem, T. & Thongtem, S. (2014). Effect of medium solvent ratios on morphologies and optical properties of α-ZnMoO4, β-ZnMoO4 and ZnMoO4 · 0.8H2O crystals synthesized by microwave-hydrothermal/ solvothermal method. Superlattice. Microst., 69, рр. 253-264. doi: https://doi.org/10.1016/j.jcrysgro.2010.02.022
8. Liang, Y., Liu, P., Li, H. B. & Yang, G. W. (2012). ZnMoO4 Micro- and nanostructures synthesized by electroche mistry-assisted laser ablation in liquids and their optical properties. Cryst. Growth Des., 12, pp. 4487-4493. doi: https://doi.org/10.1021/cg3006629