Fabrication of pillared MFI zeolite with enhanced stability in the alkylation of phenol and tert-butyl alcohol

The 2D pillared MFI zeolite is fabricated through the vapor phase pillarization (VPP) strategy with additional TPAOH, the TPAOH species can enhance the stability of pillared MFI zeolite by generation of zeolite nanocrystals in MFI nanosheet assemblies, which could act as “zeolitic pillar” to support the multiple-layered structure of MFI zeolite rather than traditional amorphous silica pillar, resulting in the formation of multiple-layer MFI nanosheets with sturdy pillars, highly opened mesopores and accessible acid sites. Especially, the resultant pillared MFI zeolite (Cry-PMFI) can effectively suppress the attack of water molecules arising from the alkylation between phenol and tert-butyl alcohol, leading to robust stability that can inhibit the collapse of ordered multiple-layered structure. In addition, the resultant Cry-PMFI also shows extraordinary activity (>75 %) and excellent selectivity of 4-tert-Butylphenol (>71 %) compared with conventional silica pillared MFI zeolites. Moreover, the ordered multiple-layered structure of Cry-PMFI is well maintained during the alkylation reaction, leading to the extended lifetime and superior regeneration property. The obtained Cry-PMFI material with solid stability has potentially technological implications in the practical application of aromatic alkylation.