Emissions catalysts- Integrating the reaction chemistry

目前的预测表明，与今天的汽油发动机相比，柴油发动机和稀燃汽油发动机在乘用车中的使用将会增加，因为它们更好的燃油经济性和更少的二氧化碳排放。巧合的是，世界上大多数国家即将出台的环境政策对大幅降低发动机尾气中的NOx、碳氢化合物、CO和颗粒物排放提出了要求。因此，正在为柴油和稀燃汽油应用开发新技术，特别是NOx。由于碳氢化合物、氮氧化物和颗粒物必须得到控制，针对每种物质的技术将出现在排气歧管中。对这些系统进行微观动力学建模通常是研究和实施新技术的最终目标。这避免了成本高昂的基于实验的测试方法，该方法必须包括所有发动机平台在许多不同的操作条件下才能保证性能。不幸的是，催化剂测试方法通常只包括气体输入和气体输出物种测量。缺少的部分是测量化学反应过程和轴向相对于流动的温度变化。滑铁卢大学和加拿大通用汽车公司(GM)提议合作，利用滑铁卢大学独特的反应器能力在通用汽车公司开发系统模型。这一努力将优化排放控制催化剂的效率，从而减少车辆排放并提高车辆的燃油经济性。

Current predictions indicate that the use of diesel and lean-burn gasoline engines in passenger vehicles willincrease relative to today's gasoline engines due to their better fuel economy and reduced CO2 emissions.Coincidentally, upcoming environmental policy throughout most of the world is imposing requirements forsignificant decreases in tailpipe NOx, hydrocarbon, CO and particulate emissions from engines. Newtechnologies are therefore being developed for diesel and lean-burn gasoline applications, with specificemphasis on NOx. As hydrocarbon, NOx and particulate must be controlled, technologies for each will bepresent in the exhaust manifold.Micro-kinetic modeling of these systems is typically the ultimate goal for those studying and implementingnew technologies. This avoids the cost prohibitive experiment-based testing method that would necessarilyinclude all engine platforms under many and diverse operating conditions to gurantee performance.Unfortunately, catalyst testing methodology typically consists only of gas in and gas out species measurements.A missing component is the measurement of the chemistry, reaction process and temperature changes in theaxial direction relative to flow. Incorporation of such information into system models enables physicalvalidation and improvements on any micro-kinetic model, or can form the basis for a new micro-kinetic modelof catalytic systems.The University of Waterloo and General Motors of Canada (GM) propose a collaboration, where the uniquereactor abilities at UW will be used to develop system models at GM. This effort will optimize emissionscontrol catalyst efficiency thereby decreasing vehicle emissions and increasing vehicle fuel economy.