丙烯选择催化还原NO的研究

在以蜂窝陶瓷为载体的Pt/Al₂O₃催化剂上，对采用丙烯选择催化还原方法来脱除稀燃发动机尾气中NO的反应进行了实验与理论研究.建立了一维非均相反应模型，对反应过程进行了模拟，从实验与理论两方面讨论了反应温度、反应物浓度、通道特征尺度等因素的影响；并对反应过程中的内、外扩散作用作了理论分析.

SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDE BY PROPYLENE

The reaction of selective catalytic reduction (SCR) of nitrogen oxide (NO) in lean-burning engine exhaust with propylene was studied on Pt/γ-Al₂O₃ supported by monolith honeycomb. A one-dimensional heterogeneous model was set up to simulate the process behavior of reactions, and the effects of factors, such as reaction temperature, reactant concentration, dimension of channel of monolith catalyst, were discussed in detail both by experiment and theory. The results predicted by the model were tested through experiments. With this model, the effects of inter- and intra-phase diffusion and other factors are discussed. The model shows that the NO conversion rate will rise when higher concentration C₃H₆ is used; the influence of hydraulic diameter is small; the reaction is controlled by the kinetics under low temperature and after the light off of C₃H₆ the internal diffusion becomes serious.