Sorption, diffusion and catalytic properties of zeolites containing 10- and 12-member ring pores in the same structure

The structure, adsorption, diffusion and catalytic properties of zeolites containing 10- and 12-member ring pores in the same structure, i.e. SSZ-33, SSZ-26, CIT-1, MCM-22, NU-86, NU-87, are presented. The adsorption and diffusion properties are well explained on the basis of the pore topologies. In those structures in which the 10- and 12-MR channels cross, the catalytic behaviour is strongly influenced by the void space left in the crossing points. This is not the case in the structures in which the pores are not connected. In this case, the catalytic performance is the average of the primary processes occurring in each one of the channels.