Ka. Bethke et al., THE ROLE OF NO2 IN THE REDUCTION OF NO BY HYDROCARBON OVER CU-ZRO2 AND CU-ZSM-5 CATALYSTS, Catalysis letters, 31(2-3), 1995, pp. 287-299
The reduction of NOx with propene or propane in the presence of 1 or 4
% O-2 was studied at low conversions over a 7.4 wt% Cu-ZrO2 and a 3.2
wt% Cu-ZSM-5 catalyst. The rates of N-2 production were compared in ex
periments using only NO or a mixture of NO and NO2 in the feed. They w
ere also compared with the rates of NO2 reduction to NO under the same
conditions, and of NO oxidation to NO2 in the absence of hydrocarbon.
It was found that the reduction of NO2 to NO was very fast, consisten
t with literature data. The data were best explained by a reaction sch
eme in which the hydrocarbon was activated primarily by reaction with
adsorbed NO2 to form an adsorbed oxidized N-containing hydrocarbon int
ermediate, the reaction of which with NO was the principal route to pr
oduce N-2 under lean NOx conditions.