The efficiency of palladium-containing MFI zeolites in the isomerization of n-hexane
Yu.G. Voloshyna, O.P. Pertko, M.M. Krylova, L.K.Patrylak, A.V. Yakovenko
V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of NAS of Ukraine
ABSTRACT
Noble metal supported zeolite isomerization catalysts are widely used in chemical industry. Recently, considerable attention has been paid to the question of maximum metal phase dispersion, while localization and uniformity of the distribution of metal particles on the support are often not taken into account. The last significantly affects on the activity and selectivity of the catalysts. The aim of this work was to assess the effect of the sequence of synthesis stages of palladiumcontaining MFI zeolites (synthesis of the acid form and metal reduction) on the size of metal particles and their localization, as well as the activity/selectivity of the catalysts in isomerization of nhexane. A number of palladium-containing catalysts based on HMFI and NH4MFI with a metal component content from 0.1 to 1.0 wt. % has been synthesized by impregnation. The study of samples by nitrogen low-temperature adsorption/desorption method showed a weak effect of palladium modification on the texture characteristics of the samples. It was found using transmission electron microscopy that the particle size of palladium increases with increase in amount of metal deposited. For almost all samples nanosized palladium particles have been recorded. The samples with palladium deposited on the hydrogen form of pentasil in the amount of 0.5 and 1.0 wt. % turned out to be the most active and most selective, however, no unequivocal dependence of the catalyst efficiency on the size of the metal particles was found.
KEYWORDS
zeolite, palladium, n-hexane isomerization, activity, selectivity
REFERENCES
- Egiazarov Yu.G., Savchits M.F., Ustilovskaya E.Ya. Getrogenno-kataliticheskaya isomerizatsyya uglevodorodov. Minsk: Nauka i tekhnika. 1989. 310 p. [in Russian].
- Poursaeidesfahani A., de Lange M.F., Khodadadian F., Dubbeldam D., Rigutto M., Nair N., Vlugt Th.J.H. Product shape selectivity of MFI-type, MEL-type, and BEA-type zeolites in the catalytic hydroconversion of heptane. J. Catal. 2017. 353. 54-62.https://doi.org/10.1016/j.jcat.2017.07.005
- Farrusseng D., Tuel A. Perspectives for Zeolite-encapsulated Metal Nanoparticles and their Applications in Catalysis. New J. Chem. 2016. 40. 3933-3949.https://doi.org/10.1039/C5NJ02608C
- Bayati B., Ejtemaei M., Aghdam N.Ch., Babaluo A.A., Haghighi M., Sharafi A. Hydroisomerization of n-Pentane over Pt/Mordenite Catalyst: Effect of Feed Composition and Process Conditions. Iranian J. Oil Gas Sci. Tech. 2016. 5 (2). 84-99.
- Anaya F., Zhang L., Tan Q., Resasco D.E. Tuning the acid-metal balance in Pd/ and Pt/zeolite catalysts for the hydroalkylation of m-cresol. J. Catal. 2015. 328. 173-185. https://doi.org/10.1016/j.jcat.2015.01.004
- Mendes P., Lapisardi G., Bouchy Ch., el Rivallan M., Silva J., Ribeiro F. Hydrogenating activity of Pt-zeolite catalysts focusing acid support and metal dispersion influence. Appl. Catal., A. 2015. 504. 17-28.https://doi.org/10.1016/j.apcata.2015.03.027
- Martins G.S.V., dos Santos E.R.F., Rodrigues M.G.F., Pecchi G., Yoshioka C.M.N., Cardoso D. N-Hexane Isomerization on Ni-Pt/Catalysts Supported on Mordenite. Modern Research in Catalysis. 2013. 2 (4). 119-126. https://doi.org/10.4236/mrc.2013.24017
- Sousa B.V., Brito K.D., Alves J.J.N., Rodrigues M.G.F., Yoshioka C.M.N., Cardoso D. n-Hexane isomerization on Pt/HMOR: effect of platinum content. Reac. Kinet. Mech. Cat. 2011. 102. 473-485. https://doi.org/10.1007/s11144-010-0273-0
- Strizhak P.Ye. Nanorazmernyye effekty v gete-rogennom katalize. Teoret. eksperim. khimiya. 2013. 49 (1). 2-21. [in Russian]. https://doi.org/10.1007/s11237-013-9297-7
- Kim J., Han S.W., Kim J.-Ch., Ryoo R. Supporting nickel to replace platinum on zeolite nanosponges for catalytic hydroisomerization of n-dodecane. ACS Catal. 2018. 8 (11). 10545-10554. https://doi.org/10.1021/acscatal.8b03301
- Patrylak K.I., Bobonych F.M., Voloshyna Yu.G., Levchuk M.M., Il'in V.G., Yakovenko O.M., Manza I.A., Tsupryk I.M. Ukrainian mordenite-clinoptilolite rocks as a base for linear hexane isomerization catalyst. Appl. Catal. A, Gen. 1998. 174. 187-198. https://doi.org/10.1016/S0926-860X(98)00196-3
- Patrilyak L.K., Manza I.A., Vypiraylenko V.I., Korovitsina A.S., Likhnevskiy R.V. Issledovaniye mekha-nizma izomerizatsii geksana s ispol'zovaniyem mikroim-pul'snogo rezhima. Teoret. eksperim. khimiya. 2003. 39. 263-267. [in Russian]. https://doi.org/10.1023/A:1025729530977
- Patrylak L.K., Krylova M.M., Pertko O.P., Voloshyna Yu.G. Linear hexane isomerization over Ni-containing pentasils. J. Porous Materials. 2019. 26. 861-868. https://doi.org/10.1007/s10934-018-0685-1
- Roldán R., Beale A.M., Sánchez-Sánchez M., Romero-Salguero F.J., Jiménez-Sanchidrián C., Gómez J.P., Sankar G. Effect of the impregnation order on the nature of metal particles of bi-functional Pt/Pd-supported zeolite Beta materials and on their catalytic activity for the hydroisomerization of alkanes. J.Catal. 2008. 254. 12-26. https://doi.org/10.1016/j.jcat.2007.10.022
- Kinger G., Vinek H. n-Nonane hydroconversion on Ni and Pt containing HMFI, HMOR and HBEA. Appl. Catal., A. 2001. 218 (1-2). 139-150. https://doi.org/10.1016/S0926-860X(01)00629-9