Quantitative Analysis of Catalysis in Hierarchical Zeolites and Surface Topology Effect Based on MFI and MWW Frameworks

Recent advances in hierarchical zeolites have demonstrated the possibility of synthesizing zeolites with microporous domains down to single-unit-cell. The improved catalytic performances of such zeolites were mostly associated with the reduced diffusion limitation in microporous regions, and the better access to active sites on external surface. Here, liquid-phase alkylation, self-etherification and de-etherification reactions are performed at mild conditions using two 10MR acid zeolites, H-self-pillared-pentasil zeolite (H-SPP) and H-MCM-22. A kinetic study with quantitative analysis of above reactions shows the dominant contribution to catalytic performance from external active sites in comparison to their 3D counterparts, and therefore the increasing importance of surface topology effect in such hierarchical zeolites.