THE ROLE OF MATRIX EMBEDDING ON THE PROPERTIES OF STEAMED MORDENITES

The influence of various hydrothermal treatments on the physicochemica l properties of pure H-mordenites and matrix-embedded H-mordenites was investigated. It was found that the crystallinity and the chemical co mposition of pure mordenite were strongly dependent on the ageing cond itions. Embedding of mordenite had no influence on the extent of dealu mination and prevented the mordenite structure from collapsing. This p rotecting effect of the matrix on the zeolite structure was not observ ed for a physical mixture MOR/matrix, thus suggesting that intimate co ntact between the zeolite and the matrix is necessary for such an effe ct to take place. This intimate contact MOR/matrix was confirmed by th e formation of new chemical bonds between hydroxyl groups on the outer surfaces of the zeolite crystals and those on the surface of the embe dding matrix. (C) 1998 Elsevier Science B.V. All rights reserved.