ISOMERIZATION OF n-HEXANE ON Pd-CATALYSTS ON PILLARED ALUMINUM-ZIRCONIUM MONTMORILLONITE

Abstract

Pd-catalysts supported on pillared aluminum-zirconium Tagan (Kazakhstan) montmorillonite (ММ) from PdCl₂ and Pd-sol were synthesized and their textural, acidic and catalytic properties in the isomerization of n-hexane were investigated, depending on content of the active metal and the temperature. It was shown that the activity and selectivity of Pd catalysts in the isomerization of n-hexane change little with decreasing of palladium content at different temperatures. On a 0.35% Pd-catalyst at 400°C, the content of C₆ isomers is 46.0%, with a decrease of the palladium content to 0.1%, the isohexanes yield is 44.0% at a temperature of 350°C. The C₆-isomers yield on the Pd-catalyst from sol is 47%, while on Pd it is 46%. A slightly increased isomerization activity of Pd-sol catalysts can be explained by a large number of average acid sites found on this catalyst as compared with the results obtained on the Pd-catalyst from PdCl₂. The particle size of palladium in a 0.35% Pd/AlZrNaHMM +HM-catalyst found for two different areas of the catalyst varies from 2.7 to 5.2 nm.

Keywords

• isomerization

References

1. [1] A.A. Ivanov, A.T. Gilmutdinov, Study of low and medium temperature isomerization of the pentane-hexane fraction, 1, 341-348. (2013). (Oil and gas business: Electron scientific j.).
2. [2] Frank Bauer, Karsten Ficht, Marko Bertmer, Wolf-Dietrich Einicke, Thomas Kuchling and Roger Gläser, Hydroisomerization of long-chain paraffins over nano-sized bimetallic Pt–Pd/H-beta catalysts, 4, 4045–4054 (2014) DOI: 10.1039/c4cy00561a (Catal. Sci. Technol.).
3. [3] N.F. Butman, N.L.Ovchinnikov, V.V. Arbuznikov, A.V. Agafonov, Synthesis and properties of Al - pillared montmorillonite of natural origin, 55, 8 , 73-77.(2012). (Chemistry and Chemical Technology).
4. [4] A. Gil, S.A. Korili, M.A. Visente, Recent Advances in the Control and Characterization of the Porous Structure of Pillared Clay Catalysts, 50, 2, 153-221. (2008). DOI:10.1080/01614940802019383 (Catalysis Reviews).
5. [5] A.S. Ivanov, Aluminum oxide and systems based on it: properties, application Catalysis and kinetics. 4, 53, 446-460 (2012). DOI: 10.1134/S0023158412040039 (Kinetics and Catalysis) .
6. [6] N.A. Zakarina, A.K. .Akurpekova, L.D. Volkova, V.P. Grigor'eva, A.A. Shapovalov, Isomerization of n-hexane on Pd - catalysts containing aluminum columnar montmorillonite 5, 3-7 (2005) (Izvestiya NAN RK).
7. [7] M.M. Malimbaeva, N.A. Zakarina, G.V. Akulova, Platinum catalysts on columnar zirconium containing montmorillonite in n-hexane isomerization 3, 27-31 (2007), (Izvestiya NAN RK.)
8. [8] P.N. Kuznetsov, L.I. Kuznetsova, A.M. Zhizhayev, High-speed synthesis of nanostructured tetragonal zirconium oxide using a mechanochemical unit, 10, 135-141 (2002). ( Chemistry for Sustainable Development).

9. [9] G.M. Maksimov, V.I. Zaikovsky, K.I. Matveyev, V.A. Likholobov, Production of colloidal solutions of metallic Pd stabilized by polyoxometalates and their supported catalysts. 41, 6, 925-932 (2000). DOI: 10.1023/A:1026641607471 (Kinetica and Catalys).