Extraframework cation distributions in X and Y faujasite zeolites: A review

The catalysis and sorption properties of faujasites depend largely on the extraframework species present, notably the cations. Following the extensive and most valuable works of Smith in 1971 and Mortier in 1982, this review paper gathers all cation distributions in X and Y type faujasite zeolites known to the authors and available in the literature by mid-2007. The cation distribution in sodium exchanged samples is analysed first. Thereafter the alkaline cation, alkaline earth cation and transition metal cation exchanged samples are dealt with. A short commentary is given at the end of each section to highlight general trends and/or contradictions between different authors if they exist.