Alternate microwave irradiation methods were used for preparing Al- and Ti-pillared clays from the natural swelling montmorillonite of Durango (Mexico) and precursor salts (AlCl3 and TiCl4). Their properties were compared with Al- and Ti-PILCS (pillared interlayered clays) prepared by conventional methods. The solids treated with microwave radiation have a stacking order with d001 of 18.8 Å for Al-PILCS and a distribution of d001 values between 14 and 22 Å for Ti-PILCS. In contrast, the conventional materials show similar interplanar spacings (d001) for Al-PILCS but a delaminated structure is always obtained for Ti-PILCS after calcining in air at 400 °C. The surface areas (BET) of the pillared clays varied between 200 and 360 m2/g. The pyridine-FTIR spectra of both series indicated mostly the presence of Lewis acid sites, up to 400 μmol Py/g. Atomic absorption spectroscopy indicated a significant variation of the Si/Al ratio for Ti-PILCS, caused by partial dealumination. Co-Mo/PILCS catalysts prepared by microwave methods were compared against CoMo/γ-Al2O3 (industrial catalysts) in the HDS of heavy vacuum gas oil derived from Maya crude (sulfur content: 2.21 wt.%). The Co-Mo/Al-PILCS from microwave radiation methods had the highest surface area (BET), i.e. 358 m2/g, and was more active with respect to the reference catalysts under the specific conditions used (32.6% versus 29.8% HDS/g(cat)). © 2002 Published by Elsevier Science Inc.
Martínez-Ortiz, M. J., Fetter, G., Domínguez, J. M., Melo-Banda, J. A., & Ramos-Gómez, R. (2003). Catalytic hydrotreating of heavy vacuum gas oil on Al- and Ti-pillared clays prepared by conventional and microwave irradiation methods. Microporous and Mesoporous Materials, 73-80. https://doi.org/10.1016/S1387-1811(02)00592-9