Cu and Co exchanged ZSM-5 zeolites -: Activity towards no reduction and hydrocarbon oxidation

vertical bar Cu-x vertical bar[SiyAl]-MFI and vertical bar Co-x vertical bar[SixAl]-MFI catalysts were prepared by ion exchange from vertical bar Na vertical bar[SiyAl]-MFI zeolites (y = 12. 25 and 45). The activity of the catalysts was evaluated in the reduction of NO to N-2 in an oxidative atmosphere using propane or methane as reducing agents. The Cu catalysts were only active with propane and they presented higher activity than the Co-based catalysts, the latter being active with both hydrocarbons. H-2-TPR and DRS-UV/Vis data allowed correlation between the activity towards NO reduction and the presence of cationic charge-compensating species in the zeolite. It was also verified that the hydrocarbons are preferentially oxidised by O-2, a reaction that occurs simultaneously with their oxidation with NO.