Catalyst silver/ceria

Lack of understanding of the above mentioned issues has led to intense study of not only what is happening on the atomic level, but also the design of new systems that have both higher selectivity and rates of conversion. Three main systems were studied thus far silver-alumina type catalysts, silver-modified manganese species, and silver-modified ceria (Ce02) systems. 

Ceria-based systems showed mixed effects for methane oxidation. Composite catalysts of Ag/Ce02 fall apart, forming large silver metal aggregates and deactivating the catalyst system (38). The only system in which silver-modified ceria found any promise is in solid oxide fuel cells utilizing yttira-stabilized zirconia however, the silver-based system was not the optimum one in this case (39). 

Shimizn, K., Kawachi, H. and Satsuma, A. (2010). Study of Active Sites and Mechanism for Soot Oxidation by Silver-loaded Ceria Catalyst, Appl. Catal. B Environmental, 96, pp. 169-175. 

Beier, M., Hansen, T. and Grunwaldt, J. (2009). Selective Liquid-Phase Oxidation of Alcohols Catalyzed by a Silver-Based Catalyst Promoted by the Presence of Ceria, J. Catal, 266, pp. 320-330. 

Aneggi et al investigated various silver-doped ceria (1-10 wt%) catalysts prepared by incipient wetness impregnation. A CeSAg catalyst exhibited the lowest 50 of the different samples tested (Zr5Ag, A15Ag). This was attributed to a different distribution of Ag/AggO over the ceria and to the fact that ceria itself is an active catalyst for soot oxidation. 

BeierMJ, Hansen TW, GrunwaldtJD. Selective Hquid-phase oxidation of alcohob catalyzed by a silver-based catalyst promoted by the presence of ceria. J Catal. 2009 266 320-330. 

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