Kinetics of selective catalytic reduction of NO by NH3 on Fe-Mo/ZSM-5 catalyst

The catalyst of Fe-Mo/ZSM-5 has been found to be more active than Fe-ZSM-5 and Mo/ZSM-5 separately for selective catalytic reduction (SCR) of nitric oxide (NO) with NH 3 . The kinetics of the SCR reaction in the presence of O 2 was studied in this work. The results showed that the observed reaction orders were 0.74–0.99, 0.01–0.13, and 0 for NO, O 2 and NH 3 at 350–450°C, respectively. And the apparent activation energy of the SCR was 65 kJ/mol on the Fe-Mo/ZSM-5 catalyst. The SCR mechanism was also deduced. Adsorbed NO species can react directly with adsorbed ammonia species on the active sites to form N 2 and H 2 O. Gaseous O 2 might serve as a reoxidizing agent for the active sites that have undergone reduction in the SCR process. It is also important to note that a certain amount of NO was decomposed directly over the Fe-Mo/ZSM-5 catalyst in the absence of NH 3 .