Structural investigations on zeolitic faujasite/benzene host/guest systems (Si/Al = 2.43 and approx= 200) by using combined powder diffraction,adsorption calorimetry and molecular mechanics simulations

摘要

The NaY(Si/Al =2.43)/benzene (1) and DAY(Si/Al = 200)/benzene (2) systems are investigated by combined adsorption calorimetry,X-ray or neutron powder diffraction and computer simulation techniques.For (1) and (2) a good estimation of the sorption heats is obtained.A complementary study of a prehydrated NaY/benzene (3) system is also realized.For (1),(2) and (3) the BZ(C)/BZ(W) ratios,the distributions (localization and population) of these two independent sorbate species and the variations of the cubic unit-cell parameters are given.In (3) two ordered WT and WII water species exist and their distributions are repotted.For this system a substantial cation migration is evidenced.In (2) two independent and totally disordered benzene species exist.It is concluded that adsorption calorimetry yields decisive informations on the adsorption mechanisms.