The Effects of Different Preparation Conditions of IR Catalyst on the Simultaneous Removal of Soot and NOx in the Presence of Rich Oxygen and H_2O as Well as SO_2

摘要

A series of Ir-supported catalysts were prepared by incipient impregnation method. The activity of Ir catalyst for the simultaneous removal of soot and NOx in the presence of rich-oxygen and H_2O as well as SO_2 has been studied, and the effects of calcination temperature, calcination time, calcination atmosphere, loading, carrier and precursor on its catalytic performance has also been investigated. Ir catalyst exhibits a high activity. With the calcination temperature increasing, Ir catalytic activity increases firstly and then decreases, and the optimal calcination temperature is 900°C. With the calcination time prolonged, Ir catalytic activity also increases firstly and then decreases, and the optimal calcination time is 3h. The optimal calcination atmosphere is 1.5vol.% H_2/N_2. Support material and precursor have a little effect on the catalytic activity, and the order is Ir/TiO_2 > Ir/ZrO_2 > Ir/SiO_2 > Ir/Al_2O_3 > Ir/ZSM-5 and IrCl(CO)[P(C_6H_5)_3]_2/ZrO_2 > H_2IrCl_6?6H_2O/ZrO_2 > IrCl_4?4H_2O/ZrO_2.