Theoretical aspects investigation of the structure of phosphormolybdenum heteropoly acid catalysts for the oxidation of methacrolein to methacrylic acid
Authors
Ismayilova Kamala, Imanova Nasiba, Bagirova Ziba, Shiraliyeva Ulkar, Huseynova Elmira, Rzayeva Aida
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The present study investigates of the structure of phosphormolybdenum heteropoly acid catalysts for the oxidation of methacrolein to methacrylic acid. As a result of the studies of the reaction of oxidative transformation of unsaturated C3-C4- aldehydes into the corresponding acids, the composition of samples with empirical formula was established: Cs0,2-1 W0,1-1 Cu0,1-0,5 Cr0,07-0,4 Zn2-4 P1 Mo12 V0,1-0,5 (NH4)1-4 Ox
The selected sample for a detailed study of the structure is as follows:
Cs0,7 W0,2 Cu0,1 Cr0,4 Zn 3 P1 Mo12 V0,3 (NH4)3-4 O 45,5 The first sample was prepared from ammonium salts of P, Mo, and V, and the second was based on phosphormolybdenum heteropoly acid. The same evaporation, drying, and calcination conditions were followed in all cases. The calcined aluminum oxide was used as a reference substance. As the results showed, regardless of the catalyst preparation method, increasing temperature up to 430°С affects its properties. These changes lead to irreversible activity loss and selectivity by 5-6 times. Presented X-ray pictures of samples that have worked for 75 hours in methacrolein oxidation mode indicate that the properties of the catalysts are unchanged. Diffractometers show that the catalyst samples are not amorphous but crystalline. The paper gives IR spectra of the catalyst samples before and after they reached stable activity. Data for the catalysts modified with cesium compared with the original heteropoly acid are presented. It is indicated that the position and relative intensity of several characteristic reflexes on the X-ray diffraction pattern change. The low catalytic activity of the samples revealed is caused by the presence on the surface of ammonia formed during the synthesis of the catalyst heating removes ammonia. The catalyst activity increases more than threefold, and the selectivity does not change. Heating of freshly prepared catalyst removes crystallization water (~170 °C). A series of experiments were conducted to determine the catalyst's thermal stability limit. Increasing of temperature to 430 °С does not affect its properties. It should be noted that the catalyst decomposition temperature is higher than that of phosphormolybdenum acid (370°C, 50° higher). This is achieved by modifying it with various additives. Thanks to the conducted research, it is possible to change the catalyst structures to improve their properties.
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Authors
Ismayilova Kamala, Imanova Nasiba, Bagirova Ziba, Shiraliyeva Ulkar, Huseynova Elmira, Rzayeva Aida
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References:
- Staroverova I.N., Kutyrev M.Yu., Khvtisiashvili L.G. Antioxidant Activity of Methano- and Cyclopentenofullerenes. Kinetics and catalysis, V.27. № 3. M., 1986. P. 691-697. (in Russian)
- Sergienko V.S., Detusheva L.G., Yurchenko E.N., Poray-Koshits M.A. Effect of Fullerene Containing a Maleopimarimide Substituent on the Kinetics of Liquid-Phase Radical Chain Oxidation of Ethylbenzene. Journal of Structural Chemistry. V. 22. № 6. 1981. P.38-42 (in Russian)
- Tillaeva S.F., Sattorov M.O. Study of the quality of oil products modified for catalysts, “Science and Education”, Bukhara. 2022. № 3. P. 123-130 (in Uzbekistan)
- Mirzaliev S.S., Yaminov F.F. Influence of modifying factors on the environment and active centers of catalysts, Engineering and Technical Institute. Bukhara. 2016. P. 38-45 (in Uzbekistan)
- Staroverova I.N., Kutyrev M.Yu. IY All-Union conference on the mechanism of catalytic reactions. Conversion of volatile organic compounds on platinum and metal oxide catalysts. M., №.2. 1986. P. 43-46. (in Russian)
- Sennerich, M., Weidler, P. Hexagonal Mo/V/W mixed oxide as a catalyst for the partial oxidation of methacrolein to methacrylic acid. Catal. Commun. 2020. 141 p. https://doi.org/10.1016/j.catcom.2020.106016
- Krauw K. Entwicklung und Einsatz einer DRIFTS-Meßzelle zur In-Situ-Spektroskopie Heterogen Katalysierter Gasphasenoxidationen; Technische Universität Darmstadt: Darmstadt. 2000. P. 235-249 (in Germany)
- Xue J., Yin H., Li H., Zhang D., Jiang T., Yu L., Shen Y. Oxidation of cyclopentene catalyzed by tungsten-substituted molybdophosphoric acids. Korean Journal of Chemical Engineering 2009. V.26. №.3. P. 654–659 (in Korean)
- Védrine J.C. Metal Oxides in Heterogeneous Oxidation Catalysis: State of the Art and Challenges for a More Sustainable World. ChemSusChem 2019. № 12. P. 577–588. DOI: 10.1002/cssc.201801974.
- Darabi M.J., Dubois J.L., Cavani F., Rostamizadeh M., Patience, G.S. Catalysis for the synthesis of methacrylic acid and methyl methacrylate. Chemical Society Reviews. 2018. P. 7703–7738. https://doi.org/10.1039/D2CS00779G
- Nagai, K.; Ui, T. Trends and Future of Monomer–MMA Technologies. Sumitomo Chem. 2004. № 2. P. 4–13. ( in Japan)
- Belousova A. S., Esipovicha A. L., Otopkova K. V. Investigation of the process of vapor-phase dehydration of glycerol to acroleiin in the presence of polyoxometallates Kinetics and catalysis. 2021. V. 61. № 4. P. 541-548 https://doi.org/10.1002/jctb.4273
- Lowell S., Shields J.E., Thomas M.A., Thommes M. Characterization of Porous Materials and Powders: Surface Area, Pore Size and Density. Netherlands: Springer, 2020. 350 p. DOI:10.1007/978-1-4020-2303-3
- Danov S.M., Esipovich A.L., Belousov A.S., Rogozhin A.E. Effect of Diethylene Glycol on the Formation of the Oxide Precursor of the Nickel–Molybdenum Hydrotreating Catalyst. Russian Journal Applied Chemistry 2019. V. 87. P. 461-469 (in Russian)
- Belousov A.S., Rogozhin A.E. Investigation of the process of vapor-phase dehydration of glycerol to acroleiin in the presence of polyoxometallates. Kinetics and catalysis. 2020. vol. 61. № 4. P.541-548 DOI: 10.31857/S0453881120030077
- Thanasilp S., Schwank J.W., Meeyoo V., Pengpanich S., Hunsom M. Comparison of citric acid and glycol effects on the state of active phase species and catalytic properties of CoPMo/Al2O3 hydrotreating catalysts. Journal of Molecular Catalisis A- Chem. 2018. V. 380. P. 67-68. DOI: 10.1016/j.mcat.2018.05.020
- Liu R., Wang T., Liu C., Jin Y. Biomass valorisation over polyoxometalate-based catalystsChin. J. Catal. 2021. V. 34. P. 2174. DOI: 10.1039/D0GC03190 A
- Abdullayeva, M.Y., Habibov, I.A. Improvement of the electrical properties of synthetic liquid dielectric for pulse capacitors. EUREKA, Physics and Engineeringthis link is disabled. 2020. P. 13–18
- Guseynova E.B., Mustafayeva R.E. Modification and study by the method of planning an experiment of a tin-antimony catalyst for the gas-phase oxidation of isobutylene to methacrolein. Natural and mathematical sciences in the modern world. Novosibirsk 2015, p. 73-83 (in Russian)
- Dong, D.Q., Yang, S.H., Wu, P., Wang, J.Z., Min, L.H., et al. Copper-Catalyzed Difluoroalkylation Reaction. Molecules 2022. 27. P.84-61. https://doi.org/10.3390/ molecules 27238461