Aluminated Derivatives of Porous Magadiite Heterostructures for Acid-Catalyzed tert-Butylation of Catechol

Novel porous magadiite/Al-magadiite heterostructures (PMH/PAMH) and aluminated derivatives of PMH (xAl-PMH, x = Al/Si in feeding) were fabricated upon two-dimensional interlayer cosurfactant-directing TEOS hydrolysis–condensation–polymerization from synthetic Na-magadiite/Na-[Al]magadiite and postgrafting of Al into the interlayer silica framework of PMH from NaAlO2 precursor, respectively. Characterization studies indicate that PMH and PAMH possess high surface area (SA), high thermal stability, and unique supermicro–mesoporous structure upon effective assembly of interlayer mesostructured silica and clay layers but weak Lewis acidity. The xAl-PMH (x = 0.2, 0.4) samples show successful incorporation of Al into interlayer mesostructure of PMH mainly in tetra-coordinated form, leading to greatly increased Lewis acidity and newly created Brønsted acidity together with well-kept layered supermicro-mesoporous porosity and reduced SA (>280 m2/g) while 0.6Al-PMH shows collapsed layers. 0.4Al-PMH exhibits the highest liquid-phase Friedel–Crafts tert-butylation activity of catechol with 93.4% conversion and 80.4% 4-tert-butylcatechol selectivity due to the strongest synergy between the surface acidity and supermicro–mesostructure.