Preparation and characterization of pillared hectorite catalysts

Abstract Reaction of natural hectorite with Al, ZrAl, and Zr polyoxycations generate pillared hectorites which after heating in air at 400 °C/4 h have Langmuir surface areas of 260–300 m 2 /g thermally stable to 600–700 °C. Spectroscopic studies of sorbed pyridine indicate that these pillared hectorites (like pillared bentonites) contain both Lewis and Bronsted acid sites distributed as in the parent (acidwashed) hectorite. Above 300 °C, in vacua , pyridine is sorbed mainly on Lewis sites. Pillared hectorites are not as active as the corresponding pillared bentonites in cracking 260–426 °C boiling range gas oils but exhibit greater gasoline selectivity and minimize light gases (C 2 –C 4 ) generation. Cracking activity depends mostly on the surface area generated by pillaring and the parent hectorite low iron content did not affect the catalyst's carbon selectivity.