Lanthanum Hierarchical SAPO-34: Synthesis, Characterization, and Catalysis Evaluation in Methanol to Propylene Process

Document Type : Research Article


1 College of Alborze, University of Tehran, Tehran, I.R. IRAN

2 Department of Organic Chemistry, School of Chemistry, College of Science, University of Tehran, Tehran, I.R. IRAN


Hierarchical SAPO-34 molecular sieve has been synthesized with n-propylamine as a mesoscale template and used to prepare La-Hierarchical SAPO-34 by impregnation by Lanthanum nitrate and has been used in Methanol-to-Propylene (MTP) conversion process. La-H-SAPO-34 demonstrated higher activity and selectivity for propylene (48.9%) compared to a conventional SAPO-34 catalyst (28.7%) in a fixed-bed reactor under atmospheric pressure at 450 oC and WHSV of 1.0 h-1. High selectivity and longer catalytic lifetime (7 hours) of methanol to propylene conversion have been attributed to the reduction in the acidic character of active sites and the increasing mesopore volume. The catalyst has been characterized by XRD, FE-SEM, BET, NH3-TPD, and TGA techniques and compared with SAPO-34.


Main Subjects

[2] Sedran U., Mahay A., De Lasa H., Modelling Methanol Conversion to Hydrocarbons: Revision and Testing of a Simple Kinetic Model, Chemical Engineering Science, 45(5): 1161-1165 (1990)
[3] Fougerit J., Gnep, N., Guisnet M., Selective Transformation of Methanol Into Light Olefins over a Mordenite Catalyst: Reaction Scheme and Mechanism, Microporous and Mesoporous Materials, 29(1-2): 79-89 (1999).
[4] Wilson S., Barger P., The Characteristics of SAPO-34 Which Influence the Conversion of Methanol
to Light Olefins
, Microporous and Mesoporous Materials, 29(1-2): 117-126 (1999).
[5] Wragg D.S., O'Brien M.G., Bleken F.L., Michiel M.D., Olsbye U., Fjellvåg H., Watching the Methanol‐
to‐Olefin Process with Time‐and Space‐Resolved High‐Energy Operando X‐Ray Diffraction,
  Angewandte Chemie International Edition, 51(32): 7956-7959 (2012).
[6] Dubois D.R., Obrzut D.L., Liu J., Thundimadathil J., Adekkanattu P.M., Guin J.A.,  Punnoose A., Seehra M.S, Conversion of Methanol to Olefins over Cobalt-, Manganese- and Nickel-Incorporated SAPO-34 Molecular Sieves - Sciencedirect, Fuel Processing Technology, 83(1): 203-218 (2003).
[7] Hajfarajollah H., Askari S., Halladj R., Effects of Micro and Nano-Sized SAPO-34 and SAPO-5 Catalysts on The Conversion of Methanol to Light Olefins, Reaction Kinetics, Mechanisms and Catalysis, 111(2): 723-736 (2014).
[8] Wu L., Liu Z., Qiu M.,  Yang Ch., Xia L., Liu X., Sun Y., Morphology Control of SAPO-34 by Microwave Synthesis and Their Performance in the Methanol to Olefins Reaction, Reaction Kinetics, Mechanisms And Catalysis, 111(1): 319-334 (2014).
[9] G.Ahangari M., R.Ranjbar P., Rashidi A.M., Teymuri M., The High Selectivity of Ce-Hierarchical SAPO-34 Nanocatalyst for the Methanol to Propylene Conversion Process,  Reaction Kinetics, Mechanisms and Catalysis, 122(2): 1265-1279 (2017).
[10] Yoon  J.W., Jhung S.H.,  Kim Y.H., Park  S.E.,  Chang  J.S., Selective Crystallization of SAPO-5
and SAPO-34 Molecular Sieves in Alkaline Condition: Effect of Heating Method,
  Bulletin of the Korean Chemical Society, 26(4): 558-562 (2005).
[12] Yang S.T., Yekim J.I., Chae  H.J., Kim M., Jeong S.Y., Ahn  W.S., Microwave Synthesis of Mesoporous SAPO-34 with a Hierarchical Pore Structure - Sciencedirect,  Materials Research Bulletin, 47(11): 3888-3892 (2012).
[14] Janssen A., Schmidt  I.,  Jacobsen  C.J.H., Koster  A.G., Jong K.P., Exploratory Study of Mesopore Templating with Carbon During Zeolite Synthesis,  Microporous and Mesoporous Materials, 65(1): 59-75 (2003).
[15] Emrani P., Fatemi  S., A.Talesh S., Effect of Synthesis Parameters on Phase Purity, Crystallinity and Particle Size of SAPO-34, Iran. J. Chem. Chem. Eng.(IJCCE), 30(4): 29-36 (2011).
[16] Nawaz Z., Chu Y., Yang W.,  Tang X.,  Wang Y.,  Wei F., Study of Propane Dehydrogenation to Propylene in an Integrated Fluidized Bed Reactor Using Pt-Sn/Al-SAPO-34 Novel Catalyst, Industrial & Engineering Chemistry Research, 49(10): 619-614 (2010).
[18] Hajiashrafi T., Nemati Kharat A., Dauth A., R.Lewis A., Preparation And Characterization of Lanthanide Modified SAPO-34 Nano Catalysts and Measurement of Their Activity for Methanol to Olefin Conversion | Springerlink, Reaction Kinetics, Mechanisms And Catalysis, 113(2): 585-603(2014).
[19] Song W., M.Marcus D., Fu  H., O.Ehresmann J., F. Haw  J.,  An Oft-Studied Reaction That May Never Have Been:? Direct Catalytic Conversion of Methanol or Dimethyl Ether To Hydrocarbons on the Solid Acids HZSM-5 Or HSAPO-34, Journal of the American Chemical Society, 124(15): 3844-3845(2002).
[20] Song W., F Haw, J., B.Nicholas  J., S. Heneghan C.,  Methylbenzenes Are the Organic Reaction Centers For Methanol-To-Olefin Catalysis on HSAPO-34, Journal of the American Chemical Society, 122(43): 10726-10727 (2000).
[21] Dai W., Wu G., Li L., Guan N., Hunger M., Mechanisms of the Deactivation of SAPO-34 Materials with Different Crystal Sizes Applied as MTO Catalysts, American Chemical Society Catalysis, 3(4): 588-596 (2013).