Mechanical stability of ZSM-5 zeolite washcoated cordierite monoliths

Abstract

ZSM-5 zeolites are washcoated on cordierite substrates by the slurry-coating and in-situ synthesis methods, respectively. A statistical approach is used to describe the mechanical stability of the prepared ZSM-5/cordierite monoliths. It is shown that both adhesive and cohesive failure take place for the slurry-coated ZSM-5/cordierite. However, for the in-situ synthesized ZSM-5/cordierite, the formation of an oriented, compact and homogeneous ZSM-5 layer leads to a very little cohesive failure, and the chemical bonding of the ZSM-5 layer to the cordierite substrate reduces the amount of adhesive failure significantly. The in-situ synthesized ZSM-5/cordierite, therefore, exhibits much higher resistances to ultrasonic vibration and thermal shock than the slurry-coated ZSM-5/cordierite. Furthermore, the in-situ synthesized ZSM-5/cordierite has high ZSM-5 loading, high surface area, high pore volume and hierarchical porosity and thus it is a good catalyst support for active species. In this study, copper and manganese are introduced by impregnation, and the prepared Cu–Mn catalyst supported on the in-situ synthesized ZSM-5/cordierite shows a satisfactory catalytic performance in o-xylene oxidation.