【摘要】 建立铁基分子筛催化剂NH₃-SCR催化反应动力学模型，用来预测催化剂的NO_x还原性能和研究SCR反应组分的轴向分布，该模型包括NH₃吸附与脱附、NH₃氧化、NO氧化、NO_x还原及N₂O生成反应．结果表明：模型能较好地预测SCR反应中各组分浓度在催化剂轴向空间的变化规律；Fe基分子筛催化剂对物质的量n（NO₂）/n（NO_x）较为敏感，最佳n（NO₂）/n（NO_x）为0.5；受NH₃抑制效应影响，当温度低于300℃时SCR反应活性较低，但是当温度高于400℃时SCR反应活性较好．此外，发现Fe基分子筛催化剂SCR反应主要集中在催化剂的入口段和中间段，300℃、空速为60 000 h^-1时在催化剂的前半段内可实现高达90%的NO_x转化率，催化剂出口段的利用率较低．最后，对模型的瞬态性能进行了考察，发现随着温度升高Fe基分子筛催化剂的瞬态响应可以得到改善．更多还原

【Abstract】 A kinetic model of NH₃-SCR catalytic reaction over Fe-zeolite catalyst was established to predict the NO_x reduction performance of the catalyst and to investigate the axial species distribution during SCR reaction. The model is composed of NH₃ adsorption and desorption,NH₃ oxidation,NO oxidation,NO_x reduction and N₂O formation reactions. The results show that the model can predict the variation of species concentration in axial space.It was found that the Fe-zeolite catalyst is sensitive to molar ratio of n（NO₂）/n（NO_x）, and the optimal n（NO₂）/n（NO_x） is 0.5. Because of the NH3 inhibition effect,the SCR activity is low at the temperature lower than 300 ℃,while high at the temperature above 400 ℃. In addition,the SCR reaction of Fe-zeolite occurs mainly in the inlet and middle segments of the catalyst. At the temperature of 300 ℃ and the space velocity of 60 000 h^-1,up to 90% NOx conversion could be achieved in the front half of the catalyst. The utilization rate of the catalyst is low at the outlet segment of the catalyst. Furthermore,the transient performance of the model was investigated,and it is found that the transient response of Fe-zeolite catalyst was improved with the temperature increasing.更多还原