Pd/Mg(Al)O催化剂上NOx的储存还原

The storage-reduction behavior of NOx(NO and NO2) on Pd/Mg(Al)O catalyst prepared by co-precipitation followed by impregnation, was investigated in a fixed-bed reactor at atmosphere and different temperatures. The catalyst was characterized by XRD and TPD. The main path of NO storage on Pd/Mg(Al)O is that Pd firstly catalyzes NO and O2 to form NO2, NO2 then reacts with Mg(Al)O to form nitrate and NO. Pd showes little effect on the formation of nitrate from NO2 on catalysts. The NOx storage capacity on Pd/Mg(Al)O has a maximum at 350℃ for NO. At this temperature the NOx storage capacity of the catalyst prepared is no less than 300μmol·g－1, and the selectivity of H2 reducing nitrate to N2 is higher than 94% even if the catalyst is performed in 15 storage-reduction cycles.