The role of the metal during NO2 reduction by C3H6 over alumina and silica-supported catalysts

The role of the metal during the reduction of NO(2) by propylene in oxygen over alumina and silica-supported gold, rhodium and platinum was studied. It was found that three parallel reactions take place, i.e., reduction of NO(2) to N(2) and N(2)O, reduction of NO(2) to NO, and oxidation of propylene. It was also found that in the case of rhodium and platinum catalysts, the reaction may proceed entirely on metallic sites and that the alumina and silica supports do not play a critical role in determining the catalytic activity for NO(2) reduction. For gold catalysts, the reaction seems to involve a combination of metal and support catalyzed processes. It was noted that the selectivity toward N(2) formation seems to be primarily influenced by the nature of the metal. (C) 1997 Elsevier Science B.V.