PROTONIC ACID SITES IN STABILIZED Y-ZEOLITES AFTER REDUCTION OF M(2+)CATIONS WITH HYDROGEN

After reduction with hydrogen, stabilized Y zeolites containing metal cations exhibit new OH groups with characteristic IR bands. Their freq uencies at 3640-3630 and 3550 cm-1 correspond to OH groups of the non- defect faujasite skeleton, which is present both in the original zeoli te lattice and in the partially dealuminated lattices of stabilized sa mples. The occupation of cationic positions by various types of cation s (Na+, AlO+, Cu2+ etc.) does not permit occupation of the bridging pr otonic sites in their microenvironment. The properties of protons crea ted after reduction of metal cations are controlled by the equalized e lectronegativity of the skeletal oxygens.