Experimental Study on Dehydration of Propane Oxidation Catalysts Based on Molybdenum over Ti-based Nanostructures

Document Type : Research Article

Authors

Olefin Laboratory, Department of Chemical Engineering, Tarbiat Modares University, Tehran, I.R. IRAN

Abstract

Propylene is one of the most important building blocks in petrochemical and polymer processes. The demand for propylene is growing faster than that for ethylene; therefore the current production is not in line with the forecast market demand for olefins. In this paper, oxidative dehydrogenation has been used in order to obtain propylene from propane, and oxygen was used as the oxidant. Molybdena-containing catalysts with nominal loading 5, 10, and 15 wt% were supported on titanate Nanotubes. Also, for the sake of comparison, Degussa TiO2 P25 supported molybdena catalyst (5 wt%) was elaborated. All catalysts were prepared by incipient wetness impregnation method and were calcined at 500°C. Analysis by FT-IR, XRD, Raman, BET, TEM, and TPR was done. The results show that the main characteristics of the titanate nanotube were confirmed by FT-IR, and the presence of H2Ti5O11.H2O was confirmed by XRD technique. Moreover, no evidence of the existence of Na-O-Ti bond was observed, and an important bond for the existence of the stable phase of the titanate nanotubes, Ti-O-H, was detected by Raman spectroscopy. TEM micrographs exhibited the layered structure of the prepared sample. The phase of the titanate nanotubes supported molybdena catalysts altered during calcination, in order to do that anatase phase was observed in all the samples. However, the rutile phase was detected along with the anatase phase in Degussa TiO2 P25 and 15 wt% supported molybdena catalyst. Calcination led to BET-specific surface area loss. The crystalline phase of molybdenum oxide of higher loading shows a higher maximum reduction peak by H2-TPR profile. As compared to titanate nanotubes, in the identical molybdena loading lower specific surface area as well as inferior catalytic activity and lesser lifetime was observed for TiO2 P25 support. However, increasing molybdena loading on the titanate nanotubes led to catalytic performance deterioration. The highest yield is for MoTNT-10 with a selectivity 31% and conversion 21.4%.

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[1] Boizumault-Moriceau P., Pennequin A., Grzybowska B., Barbaux  Y., “Oxidative Dehydrogenation of Propane on NiCeO Oxide: Effect of the Preparation Method, Effect of Potassium Addition and Physical Characterization,Appl. Catal. A Gen., 245(1): 55-67 (2003).
[2] Testova N.V., Shalygin A.S., Kaichev V.V., Glazneva T.S., Paukshtis E.A., Parmon V.N., Oxidative Dehydrogenation of Propane by Molecular Chlorine, Appl. Catal. A Gen., 505: 441-446 (2015).
[3] Cavani F., Ballarini. N., Cericola. A., Oxidative Dehydrogenation of Ethane and Propane: How Far from Commercial Implementation?,” Catal. Today, 127(1-4): 113-131 (2007).
[4] Pieck C.L. Bañares M.A. Fierro J.L.G. Propane Oxidative Dehydrogenation on VOx/ZrO2 Catalysts,” J. Catal., 224(1): 1-7 (2004).
[5] Kootenaei A.H.S., Towfigh. J., Khodadadi A., Mortazavi. Y., Stability and Catalytic Performance of Vanadia Supported on Nanostructured Titania Catalyst in Oxidative Dehydrogenation of Propane, Appl. Surf. Sci., 298: 26-35 (2014).
[6] Tania M., Costa H., Gallas M.R., Benvenutti E.V., da Jornada J.A.H., “Study of Nanocrystalline γ-Al2O3 Produced by High-Pressure Compaction,” (1999).
[7] Heracleous E., Machli M. Lemonidou, A.A. Vasalos I.A., Oxidative Dehydrogenation of Ethane and Propane Over Vanadia and Molybdena Supported Catalysts, J. Mol. Catal. A Chem., 232(1–2): 29-39 (2005).
[8] Putra M.D., Al-Zahrani S.M., Abasaeed A.E., Oxidehydrogenation of Propane to Propylene Over Sr-V-Mo Catalysts: Effects of Reaction Temperature and Space Time, J. Ind. Eng. Chem., 18(3): 1153-1156 (2012).
[10] Bavykin D.V., Walsh F.C., “Titanate and Titania Nanotubes“. Cambridge: Royal Society of Chemistry, (2009).
[11] Kemdeo S.M., Sapkal V.S., Chaudhari G.N., TiO2-SiO2 Mixed Oxide Supported MoO3 Catalyst: Physicochemical Characterization and Activities in Nitration of Phenol, J. Mol. Catal. A Chem., 323(1-2): 70-77 (2010).
[13] Kootenaei A.H.S., Towfighi J., Khodadadi A., Mortazavi Y., Stability and Catalytic Performance of Vanadia Supported on Nanostructured Titania Catalyst in Oxidative Dehydrogenation of Propane, Appl. Surf. Sci., 298: 26-35 (2014).
[14] Murgia V., Farfán Torres E.M., Gottifredi J.C., Sham E.L., Influence of Concentration and Order of Aggregation of the Active Phases in V-Mo-O Catalysts in the Oxidative Dehydrogenation of Propane, Catal. Today, 133-135(1-4): 87-91 (2008).
[15] Sasikala R., Sudarsan V., Sakuntala T., Jagannath., Sudakar C., Naik R., Bharadwaj  S.R., Nanoparticles of Vanadia–Zirconia Catalysts Synthesized by Polyol-Mediated Route: Enhanced Selectivity for the Oxidative Dehydrogenation of Propane to Propene, Appl. Catal. A Gen., 350(2): 252-258 (2008).
[16] Palcheva R., Dimitrov L., Tyuliev G., Spojakina A., Jiratova K., TiO2 Nanotubes Supported NiW Hydrodesulphurization Catalysts: Characterization and Activity, Appl. Surf. Sci., 265: 309-316 (2013).
[17] Wong C.L., Tan Y.N., Mohamed A.R., A Review on the Formation of Titania Nanotube Photocatalysts by Hydrothermal Treatment, Journal of Environmental Management, 92(7): 1669-1680 (2011).
[19] Varzaneh A.Z., Moghaddam M.S., Darian J.T., Oxidative Dehydrogenation of Propane Over Vanadium Catalyst Supported on Nano-HZSM-5, Pet. Chem., 58(1): 13-21 (2018).