| Cumene disproportionation can be applied as a probe reaction for investigation of zeolite acidities and structures, and it is also an important process for the synthesis of m-diisopropylbenzene (m-iiPB) and p-diisopropylbenzene (p-iiPB) which are important intermediates in the polymer industry. However, in cumene disproportionation there are disadvantages such as low selectivity of primary reaction, low conversion and equal selectivities for m-iiPB and p-iiPB. To eliminate these problems, much attention has been paid to the development of solid catalysts. In this thesis, it is proposed to combine the pore structure and acidity of HP with the B acidity of layered zirconium sulfate tetrahydrate, and a series of novel Hp-supported Zr catalysts (Zr/Hp) have been designed and prepared. The catalyst shows high catalytic activity and selectivity for cumene disproportionation.According to the individual catalytic performance and structures of layered zirconium sulfate tetrahydrate and HP zeolite, it was proposed that layered zirconium sulfate tetrahydrate be well-dispersed over the surface of HP zeolite, so that the acidic sites located in the interlayer regions oflayered zirconium sulfate tetrahydrate can be exposed to the surface of Hp zeolite. According to this hypothesis, a series of HP-supported Zr catalysts (Zr/Hp) were prepared.The surface state of Zr/Hp was studied and the results show that the threshold of monolayer dispersion of layered zirconium sulfate tetrahydrate over HP is 0.5367g Zr(SO4)2-4H2O/g Hp. It is almost consistent with the calculated result using compact monolayer dispersion model. The relation between the quantity of zirconium sulfate tetrahydrate and the crystallinity of Zr/Hp clearly shows that zirconium sulfate tetrahydrate is dispersed in an amorphous monolayer when the loading is below the threshold value.The short range order of Zr/Hp has been studied using EXAFS and the results show that each zirconium on Zr/Hp has 4.8 nearest oxygen at an average distance of 2.16A. Zr atoms in the catalyst possibly exist in a ZrO7 coordination environment and there are structural feature associates with unsaturation.Surface acidities and pore structure of Zr/Hp and Hp have been investigated using pyridine adsorption TPD and nitrogen adsorption-desorption isotherms. The results show that the weakly acidic centre of Zr/Hp are weaker than those of HP and the strongly acidic center of Zr/Hp are stronger than those of Hp. As a result, the activitiy of Zr/Hp is much higher than that of HP, and the disproportionation selectivity of Zr/Hp is slightly higher than that of HP, but the initial disproportionationselectivity of Zr/Hβ3 is lower than that of Hβ. The pore sizes of Zr/Hβ and HP are very similar, so the molar ratio of m-/p- diisopropylbenzene in the cumene disproportionation products over Zr/Hβ is very similar to that observed over Hβ.Cumene disproportionation has also been studied over microporous zeolites, mesoporous zeolites and layered catalysts on the basis of optimizing reaction conditions. The results show that the optimal reaction conditions are cumene/N2=12(mol/mol), and reaction temperature 180C. Both the acidity and pore structures have a great effect on the activities of the catalysts and the product distribution in cumene disproportionation. To some extent, the stronger the acidity of the catalyst, the greater the catalytic activities. Strongly acidic catalysts favor cumene cracking however. The formation of iiPB is highly shape-selective. The m-iiPB to p-iiPB ratio is greater for zeolites and layered structure catalysts with large pore openings.
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