Synthesis Of COK-5and Their Catalytic Properties For Alkylation Of Toluene With Methanol

With the continuous development and utilization of oil resources, the demand foroil is running high which makes the traditional PX preparation process can not meetpeople’s need. Conversely methanol is in an excess of supply over demand. For thisreason, toluene alkylation with methanol to PX which methanol is the reactant attractspeople’s interest. And what’s more, By this means high concentrations of PX isobtained by following the process of one-step synthesis, which simplifies separationand purification so that increases economic value.In general, toluene alkylation reaction happens when acid zeolites as catalyst.ZSM-5and modified ZSM-5on this reaction Achieved significant results. But thereexist some problems such as low conversion of toluene and low catalyst stability. So,to develop catalyst with high activity, high selectivity and high stability becomes thenew challenge in future.For now，the relative catalysts are confined to the ZSM-5, Mordenite, Y zeoliteand SAPO-n et al. Thus to develop new catalyst system becomes the increasinglyimportant part of the research. In our previous work, a novel zeolite with specific porestructures attracts our intentions. The intergrowthed COK-5may have four types ofpores circumscribed with10-or12-rings, and the open galleries at the channelcrossing may be widened by the side pockets facing each other; and one specialfeature is that the12-ring pores present in COK-5could be so distorted that they aremore like10-ring pores, which have never been discovered in other zeolites. Withouta doubt, these unique structure characteristics may promise high catalytic potential.However, there are no continuous report concerning the studies of thephysicochemical properties (e.g., acidity and texture) and the catalytic performance ofCOK-5.On the basis of our previous work, we further investigated how the synthesisfactors such as crystallization temperature, crystallization time, seed influence theCOK-5crystallization. At the same time we prepared a series of modified COK-5for toluene alkylation reaction and investigated the relationships between reactioncondition and the selectivity, activity and stability so that develop proper catalyst.