Montmorillonites Modified with Carbonaceous Deposits.

The mechanism of formation of carbonaceous deposits on montmorillonites was studied for systems prepared by sorption of polymers on pillared montmorillonites and subsequent carbonization. Temperature-programmed desorption of ammonia and X-ray photoelectron spectroscopy showed that polymer was attached to Al-OH acidic sites of smectite layers. Pillars were not influenced to a greater extent. Islands of carbonaceous material were formed, but the amount of deposited carbon depended strongly upon carbonization conditions. The hydrophylic and acidic properties of carbon-covered silica aluminas differed strongly from those of the starting material. Copyright 2000 Academic Press.