TEMPERATURE-PROGRAMMED DESORPTION OF NITRIC-OXIDE OVER CU-ZSM-5

Room temperature adsorption and temperature-programmed desorption (TPD) of NO over a Cu-ZSM-5 catalyst active for NO decomposition were investigated. Even at 25-degrees-C N2O and N2 were observed as reaction products during NO adsorption, but they ceased when NO adsorption was completed. During NO TPD, N2O, NO and O2 desorption peaks were observed. A relatively low temperature oxygen desorption peak was detected at ca. 360-degrees-C. No decomposition was detected without copper present. NO TPD was also collected over reduced and oxidized catalysts. In addition nitrous oxide and NO2 adsorptions and their TPDs were obtained over the catalyst in order to understand the interaction of NO with the catalyst. TPD studies with NO2 implicate the presence of NO2 on the catalyst.