Modulating isomers distribution of n-dodecane hydroisomerization by mordenite-ZSM-22 composite zeolite

Mordenite-ZSM-22 composite zeolite is prepared by the physical mixing. The structure, pore properties, acid properties and diffusion properties of samples are characterized by the means of XRD, N 2 physical adsorption-desorption, SEM, TEM, NH 3 -TPD, Py-IR, and ZLC. The pore properties and acid properties of mordenite-ZSM-22 composite zeolite can be efficiently modulated by changing mass ratio of mordenite and ZSM-22. In n -C 12 hydroisomerization reaction, Pt/HMZ- x displays great capacity in modulate n -dodecane isomers distribution (mono-branched i -C 12 , multi-branched i -C 12 , terminal branched i -C 12 and central branched i -C 12 ), these results are ascribed to that these composite zeolite catalysts combined the topology structure advantage of mordenite and ZSM-22. When reaction temperature is 280 °C, the ratio of mono-branched i -C 12 selectivity to multi-branched i -C 12 selectivity (S MB /S MTB ) of Pt/HZSM-22, Pt/HMZ-1, Pt/HMZ-3, Pt/HMZ-5 and Pt/HMOR were 37.64, 15.04, 5.48, 5.20 and 1.47, respectively. The ZLC diffusion experiment results indicate that low isomer selectivity of Pt/HMOR is due to its poor diffusivity. On the contrary, Pt/HZSM-22 favors the diffusion of reactants and has better catalytic performance. • MOR-ZSM-22 zeolite can efficiently modulate i -dodecane distribution. • Textural and acid properties were regulated by adjusting MOR and ZSM-22 mass ratio. • MOR-ZSM-22 zeolite-metal catalyst can produce high quality lube base oil.