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Review Canada GIK 7P4This paper is an extensive review of the literature dealing with the class of catalytic membrane reactors which involves hydrogen permeable membranes made of palladium and palladium alloys. The fundamental factors which affect hydrogen permeability are first discussed. A classification of the many reactions which have been conducted in such reactors at both laboratory and commercial scales is then presented. The various techniques for the preparation of palladiumbased membranes are described and the literature on modeling and design of these reactors is also reviewed.Cet article passe en revue la littkrature relative B une classe de rkacteurs catalytiques z1 membranes utilisant des films de palladium ou d'alliages de palladium permtables a I'hydrogtne. On discute en premier lieu les facteurs qui affectent cette permeabilitk. On prCsente une classification des diverses rCactions et prockdes qui ont 6tC effectuCs dans de tels rtacteurs, au laboratoire et a I'kchelle commerciale. Les diverses techniques de prtparation des membranes 2 base de palladium sont dkcrites et on examine aussi la IittCrature portant sur la modClisation et la conception des rtacteurs.

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Catalytic activity for CH 4 oxidation and resistance to SO 2 poisoning were tested for three LaCo 1-X Fe X O 3 prepared by reactive grinding. The catalysts prepared by this method showed well-crystallized perovskite structure and various specific surface areas. The activity in CH 4 oxidation correlates well with BET specific surface area. TPDO experiments showed very large quantities of desorbed β-oxygen that could not be correlated to the activity for CH 4 oxidation. Resistance to sulfur poisoning in the same reaction was tested at 500 °C with 25 ppmv SO 2 added to the feed. Two steps were distinguished during the poisoning reaction. The first one followed an exponential decrease of conversion versus time. The time to reach the end of this step was shown to be directly proportional to the specific surface area. In this step, deactivation was found to be reversible. During regeneration, some sulfur species were found to desorb from the catalyst. The second step was found to be a linear diminution of conversion with time. The slopes of these lines were found to be the same for the three catalysts. A total of 860 h is necessary to deactive the catalyst with the higher specific surface area, and the quantity of sulfur accumulated in the catalyst was found to vary linearly with the poisoning time. XRD showed significant conversion of the catalyst into La 2 (SO 4 ) 3 , Co 3 O 4 , and iron oxide. The complex poisoning behavior is discussed and associated to the observed differences in the catalyst morphology.

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