Article ID Journal Published Year Pages File Type
63282 Journal of Catalysis 2006 6 Pages PDF
Abstract

The oxidation of CO was studied over a Au/TiO2 reference catalyst in a static reactor coupled to a thermodesorption device. The optimal vacuum activation/regeneration temperature is in the range 350–400 °C. The catalyst partly deactivates during the first runs, possibly through poisoning of the active sites by carbonate-like species, whose formation is clearly evidenced. Although a postreaction treatment under pure hydrogen is ineffective toward regeneration, the catalyst gradually recovers its initial activity for CO conversion in the presence of a low amount of hydrogen within the reactant mixture. Increasing the hydrogen pressure only promotes the oxidation of hydrogen, thereby decreasing selectivity in the preferential oxidation of CO. Consequently, we show that hydrogen-induced promotion of Au/TiO2 is a regeneration effect involving removal of carbonates rather than a boosting effect via new CO oxidation pathways.

Related Topics
Physical Sciences and Engineering Chemical Engineering Catalysis
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