III International Conference

PP-I-57activity of synthetic catalysts. Results of n-hexane isomerization are given in table 2 at ratio2,5; 5,0 and 7,5mmole Al 3+ /g MM.Table 2 – Hydroisomerization n-hexane on Pt-, Pd- and Ni-catalysts at 350-400 0 C.α,% Si-B 2MB 2,2DMCatalyst T 0Composition of reaction products, %CC6+n-2MP 3MP 2,4D 3,3DMC 5 BMP PPt/AlMM 350 58,1 100 - - - 0,5 38,6 18,3 - 0,7(2,5mmole/g) 400 53,5 100 - - - - 29,4 24,1 - -Pt/AlMM 350 39,0 99,5 - - 0,1 1,5 20,7 13,9 1,3 1,5(5mmole/g) 400 46,9 98,1 0,9 - - 1,9 21,1 14,4 3,0 5,6Pt/AlMM 350 49,8 98,8 0,5 - 0,1 2,4 26,7 17,1 1,2 1,8(7,5mmole/g) 400 50,1 97,2 0,9 0,2 0,3 1,9 21,8 14,7 3,3 7,0Pd/AlMM 350 29,3 100 - - - 0,3 7,3 21,7 - -(2,5mmole/g) 400 37,2 100 - - - 1,0 20,8 14,3 0,4 0,7Pd/AlMM 350 28,9 100 - - - 0,1 18,6 10,0 0,1 0,1(5mmole/g) 400 51,8 100 - - - 9,0 26,6 16,0 0,1 0,1Pd/AlMM 350 25,3 100 - - - 0,4 16,8 8,0 0,1 -(7,5mmole/g) 400 19,4 100 - - - 0,5 11,3 7,6 - -Ni/AlMM 350 8,7 87,4 - - 1,1 - 4,3 3,0 0,3 -(2,5mmole/g) 400 10,6 92,5 - - 0,8 - 5,3 3,7 0,4 0,4Ni/AlMM 350 4,5 100 - - - 0,5 2,0 1,6 0,4 -(5mmole/g) 400 23,4 100 - - - - 1,0 0,8 0,4 21,2Ni/AlMM 350 4,9 98,0 - - 0,1 - 2,6 2,0 0,2 -(7,5mmole/g) 400 5,3 96,2 - - 0,2 - 3,4 1,4 0,3 -n-C 5 -pentane; i-B-izobutane; MB-methylbutane; DMB-dimethylbutane; MP-methylpentane;DMP-dimethylpentanePractically full absence of hydrocracking products is characteristic peculiarity ofisomerization on the pillared MM. The Pt-catalyst showed the highest conversion (58,1 %), thePd/AlMM gave 51,8 % conversion and Ni - 23,4 %. The reaction took place with 100 %selectivity to C 6+ -hydrocarbons. According to the electron microscopy data in the case ofpreliminarily reduced samples Pt- and Pd metal particles covered surface of carrier uniformly.Sizes of Pt particles were 30-50 Å and Pd - 50-110Å. Ni-catalysts contained an agglomeration ofsmall particles with different degree of reduction (NiO, Ni 2 O 2 ). Reduction didn’t take place.Absence of micropores and homogeneous distribution of metal particles can be thepossible reason of high selectivity of metals on the AlMM surface.NH 3 TPD results were shown that Al(2,5) MM had optimal acidity 277,5 mkmole NH 3 /gMM. Share of weak acid centers was 58,7 %. Introduction of metals increased the content ofweak acid centers to 8,7-13 %. It was shown that the conversion of n-hexane with the contentof middle (200-300 o C) acid centers (mkmole NH 3 /g MM): Pt(76,6)>Pd(76,4) >Ni(64,8)correlated.References1. Figueras F. //Catal. Rev.Sci.Eng. 1988. V 30. P. 457-499.2. Zakarina N.A., Akurpekova A.K., Volkova L.D., Grigorieva V.P., Schapovalov A.A. //IsvestiaNAS RK, seria chimicheskaia (Russian), 2005. № 6. С. 1-7.108