Unravelling the Crucial of Spatial Al Distribution to Realize Precise Alkali‐Treatment for Target Acid‐Catalyzed Reactions

Constructing mesoporous structure within zeolites by alkali-treatment is an effective protocol to improve their diffusion properties. However, undesirable changes in Brönsted acid site (BAS) densities always offset this advantage in acid-catalyzed reactions. In this context, the crucial roles of spatial aluminum (Al) distribution were unraveled during alkali-treatment of MFI zeolite and the desirable BAS density was achieved in obtained hierarchical samples for the target reactions. Various characterization methods, particularly the multiple one- and two-dimensional magic-angle spinning (MAS) NMR techniques, were performed to track the alkali-treatment processes. For the sample with a more uniform spatial Al distribution, more tetrahedral Al sites would fall off and migrate around the Si-OH in zeolite as Al(OH)