(617t) Dimerization of Bicyclo[2.2.1]Hepta-2,5-Diene over Zeolite Catalysts

Norbornadiene (NBD, bicyclo[2.2.1]hepta-2,5-diene) dimer can be used as a high-energy densty fuel. Dimerization of NBD needs to be promoted by a catalyst.  Recently, the homogeneous catalysts have been used in the NBDD manufacturing process. If a homogeneous catalyst is used, the cost of a catalyst is high and the separation process is quite complicated. If a homogeneous catalyst is replaced with a heterogeneous catalyst in the NBDD manufacturing process, recovery and reuse of a catalyst are possible and therefore the cost of a catalyst can be innovatively reduced[6]. The aim of the study is to verify availability of zeolite and mesoporous materia as heterogeneous catalysts for NBD dimerization. In this work, we conducted a research for the dimerization of NBD over a solid catalyst. Zeolite beta and the mesoporous materials produced from zeolite beta (MMZ _Hβ) were used for the dimerization of NBD. A batch reactor(160 ml) was used for mechanical agitation. Zeolite, NBD and toluene as a solvent were put into the batch reactor and the reactor was purged with nitrogen. The reaction was conducted at 150 â?? 300 ºC. Cooling water was supplied through cooling coils in the reactor in order to keep constant temperature. The products were collected every three hours and analyzed by GC. Zeolite used as a catalyst was purchased from Zeolyst Co. Hβ zeolite was decomposed in the alkali solution and a mplating agent was added to the solution. Then, a mesoporous material was produced by hydrothermal synthesis. The catalyst which had both micropore and mesopore was named MMZ_Hβ.  Though the amount and the strength of acid sites over MMZ_Hβ decreased compared with zeolite beta, the MMZ_Hβ catalyst shows high reaction activity and selectivity in a dimerization of NBD, which can be attributed to the large pore size of MMZ_Hβ which is favorable for the diffusion of reactant, intermediate, and product.