Annulation of phenols: Catalytic behavior of conventional and 2D zeolites

Abstract

Catalytic behavior of MFI zeolites differing in thickness of nanosheets and ordering was studied in annulation of phenols, and compared with 3D zeolites BEA and MFI containing large or medium pores as well as with micro/mesoporous zeolite USY. The highest conversions of phenols studied were achieved over ordered hexagonally mesostructured zeolite with 1.7 nm wall size, followed by materials possessing 2.1 and 2.7 nm of nanosheets thickness. This corresponds to decreasing surface area of materials studied. The preferences of materials with zeolitic layers and high surface areas over bulky zeolites BEA and especially MFI in annulation of phenols is more prominent for substrates with larger kinetic diameters [phenol(0.66 nm)<1-naphthol (0.80 nm)<2-naphthol (0.89 nm)]. USY zeolite exhibited higher conversions (32, 6, 25% for phenol, 1-and 2-naphthol, respectively, after 300 min time on stream) than BEA (23, 6, 8%) and MFI (13, 0, 0%) not overcoming hexagonally mesostructured MFI (45, 36, 55%).