NO catalytic activity of selective catalytic reduction with ammonia (NH_3) by CuMn-ZSM-5 catalysts

CuMn-ZSM-5 catalysts were prepared by incipient impregnation method,and NO catalytic activity of selective catalytic reduction(SCR) of the catalysts with ammonia(NH3) in micro gas-solid reaction device were studied and compared.Furthermore,the effects of reaction temperature,the mole ratio of Cu-Mn and the loaded mass on the catalytic activity were also studied.In addition,XRD and SEM experiments were carried out to study the physical and chemical properties of the catalysts.The results show that NO catalytic activity of Na-ZSM-5 is the lowest,and the Cu-ZSM-5 can yield higher NO conversion than that of Na-ZSM-5,but its NO conversion ratio is low when temperature is higher than 350 ℃.The catalytic activity of Mn-ZSM-5 is lower than that of CuMn-ZSM-5 when temperature is lower than 450 ℃.NO catalytic activities of series of CuMn-ZSM-5 are almost wholly superior to those of Cu-ZSM-5 and Mn-ZSM-5.The NO conversion ratio is over 80% between 250 ℃ and 500 ℃ when the loading is 4.5 mmol/g and the mass ratio of Cu and Mn is 2:1.The catalyst of 2:1 CuMn-ZSM-5 can yield over 80% NO conversion,which is the highest NO conversion ratio among series of CuMn-ZSM-5 catalysts.