The Effect of Vanadium Loading on the Performance of Ti-phosphate-supported V2O5 Catalyst in the Selective Oxidation of o-xylene to Phthalic Anhydride

Document Type : Research Article

Authors

Chemical Engineering Department, Iran University of Science and Technology, Tehran, I.R. IRAN

Abstract

In this work, the performance of Ti-phosphate-supported vanadium (v) oxide catalyst in The reaction of phthalic anhydride production by selective catalytic oxidation of o-xylene was investigated. Four catalyst samples with the active phase of 2, 7, 12 and 15 wt% were made in order to investigate the effect of vanadium loading.To determine the characteristics of samples, a number of experiments such as BET, XRD, SEM, NH3-TPD, and TGA were done. Moreover, the reactor test was carried out in order to evaluate activity and selectivity to phthalic anhydride. According to XRD patterns before the reaction, titania was observed in the anatase phase which was the desirable phase for the reaction of o-xylene oxidation to phthalic anhydride. With increasing vanadium loading, the number of acidic sites on catalyst surface decreases. In addition, the catalytic activity and selectivity to phthalic anhydride were improved. At high values of vanadium, the effect of active phase loading on the catalytic performance decreased due to the formation of V2O5 on the catalyst surface. 15V-Tip sample had the most selectivity to phthalic anhydride with values of 37% at the temperature of 450oC.

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[1] Wang Y., Zhang C., Yu Y., Yue R., Ordered Mesoporous and Bulk Co3O4 Supported Pd Catalysts for Catalytic Oxidation of o-Xylene, Catalysis Today 242, Part B: 294-299(2015).
[2] Sethapokin P., Kunatippapong S., Lothongkum A., Estimation of Kinetic Parameters for the Reactor Model of the Phthalic Anhydride Production by the Design of Experiments, Journal of Industrial and Engineering Chemistry, 24: 51-58 (2015).
[3] Cavani, F., Caldarelli, A., Luciani, S., Cortelli, C., Cruzzolin, F., Selective Oxidation of o-Xylene to Phthalic Anhydride: from Conventional Catalysts and Technologies toward Innovative Approaches, Catalysis, 24: 204-222 (2012).
[5] Marx R., Wölk H., Mestl G., Turek T., Reaction Scheme of o-Xylene Oxidation on Vanadia Catalyst, Applied Catalysis A: General, 398(1-2): 37-43 (2011).
[6] Scirè S., Liotta L., Supported Gold Catalysts for the Total Oxidation of Volatile Organic Compounds, Applied Catalysis B: Environmental, 125: 222-246 (2012).
[7] Lee D.W., Yoo B., Advanced Metal Oxide (Supported) Catalysts: Synthesis and Applications, Journal of Industrial and Engineering Chemistry, 20(6): 3947-3959(2014).
[8] Cha W., Chin S., Park E., Jurng J., Effect of V2O5 Loading of V2O5/TiO2 Catalysts Prepared via CVC and Impregnation Methods on NOx Removal, Applied Catalysis B: Environmental, 140–141: 708-715 (2013).
[13] Rao K., Venkataswamy P., Bharali P., Reddy B., Monolayer V2O5/TiO2–ZrO2 Catalysts for Selective Oxidation of Oxylene: Preparation and Characterization, Research on Chemical Intermediates, 38(3-5): 733-744 (2012).
[14] Jones D.J., Aptel G., Brandhorst M., Jacquin M., Jiménez-Jiménez J., Jiménez-López A., High Surface Area Mesoporous Titanium Phosphate: Synthesis and Surface Acidity Determination, Journal of Materials Chemistry, 10(8): 1957-1963(2000).
[16] Cavani F., Cortelli C., Frattini A., Panzacchi B., Ravaglia V., The Characterization of the V Species and the Identification of the Promoting Effect of Dopants in V/Ti/O Catalysts for o-Xylene Oxidation, Catalysis Today, 118(3–4): 298-306 (2006).
[18] Luciani S., Ballarini N., Cavani F., Cortelli C., Cruzzolin F., Anatase-Supported Vanadium Oxide Catalysts for o-Xylene Oxidation: From Consolidated Certainties to Unexpected Effects, Catalysis Today, 142(3-4): 132-137(2009).
[21] Gimeno M.P., Gascón J., Téllez C., Herguido J., Selective Oxidation of o-Xylene to Phthalic Anhydride Over V2O5/TiO2: Kinetic Study in a Fluidized Bed Reactor, Chemical Engineering and Processing: Process Intensification, 47(9–10): 1844-1852(2008).
[24] کوشکی، عماد؛ روشن ضمیر، سوسن؛ بهینه سازی لایه کاتالیست کاتدی در پیلهای سوختی غشای تبادل پروتون، نشریه شیمی و مهندسی شیمی ایران، (3)34: 21 تا 30 (1394).
[25] جورشعبانی، میلاد؛ بدیعی، علیرضا؛ لشگری، نگار؛ تهیه و شناسایی نانو متخلخل V-SBA-16 و کاربرد آن به عنوان کاتالیست در فرایند اکسایش مستقیم بنزن به فنل، نشریه شیمی و مهندسی شیمی ایران، (3)34: 13 تا 20 (1394).