H2 purification-related CO oxidations

H2 Purification-Related CO Oxidations Water-Gas Shift (WGS) and PROX Reactions 459... 

The preferential CO oxidation in H2-rich streams is a reaction of great relevance due to its application in the purification of feeds for hydrogen fuel cells, and because of the scientific interest. This reaction is known to be very sensitive to catalytic surface structures and to the pretreatments. Au catalysts supported on metal oxides with high metal dispersions have been demonstrated as very effective in this PROX reaction [1]. However, the studies carried out over these systems have allowed us to conclude that several factors affect the performance of the catalyst, such as particle sizes, preparation method, supports, etc. Nevertheless, there is still some controversy with respect to the nature of the active site or about the mechanism of reactioa In the present conununication and with the aim to obtain further information to elucidate these unresolved points a study on the role of the support in the CO PROX mechanism, particularly emphasizing in the aspects related to the preparation of Au-supported catalysts is presented. The use of a TAP (Temporal Analysis of Products) reactor is also applied to reveal elementary processes that are taking place on the surface under reaction conditions, since this reactor system allows the detection of reactants and products with a submilhsecond time resolution [2]. 

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