TG/DTG/DTA study on interaction between the framework of high silica hydrophobic FAU zeolite and adsorbed organics

High silica hydrophobic FAU zeolite with perfect framework was prepared and used to study the interaction between the framework and 25 adsorbed organi c compounds with TG/DTG/DTA, The compounds studied were hydrocarbons, alcoh ols, organic acids, chloro-containing organics, alkylamines, and esters. Th e saturating capacities of adsorption were measured. The affinity index A(T ) was determined and used to evaluate the interaction between the framework of the zeolite and the adsorbates. Different A(T) value reveals unlike int eraction. The Si-O-Si framework of the zeolite shows a stronger affinity wi th saturated hydrocarbons than with unsaturated ones, and usually phobic wi th the alkylalcohols and organic acids. The special sorbate/framework and s orbate/sorbate interactions for certain organics, such as amines, can be id entified from the very high A(T) values, the double peaks in the DTG curves , and thermal effects in the DTA curves. The tendency of A(T) values for th e adsorbed organic species on high silica hydrophobic FAU zeolite is simila r to that on high silica hydrophobic MFI zeolite. An index of S-T, the adso rption density on the framework, is higher for MFI zeolite than for FAU zeo lite, leading to the lower A(T) value of a certain adsorbate on FAU zeolite than on MFI zeolite.