用于NH3-SCR的高硅铝比Cu/LTA催化剂的制备及其催化机理的研究

氨选择性催化还原技术因其高效、环保、成本较低等优势被广泛应用于柴油车尾气中氮氧化物的净化处理。高硅铝比Cu/LTA分子筛催化剂在NH3-SCR反应中表现出优异的水热稳定性和良好的催化性能，为稀燃氮氧化物催化还原研究指明了一个新的方向。然而低温活性、副产物生成以及催化剂中毒仍是Cu/LTA催化剂实际应用中亟需解决的关键问题。本项目拟通过有效调控催化剂中Cu活性位点分布，研究催化剂制备的关键工艺参数对Cu活性位点分布的影响，探明催化剂的物化性质与其低温催化性能、副产物生成、水热稳定性以及中毒机制的关联规律；通过分析催化活性组分差异对催化反应的影响，研究反应物在不同反应阶段的催化反应路径和催化活性中心，结合运用多种物化表征手段及理论计算，推断低温催化反应过程中的活性中心、O2的活化路径及催化反应机理。本项目为Cu/LTA催化材料设计开发的关键参数提供重要的实验和理论研究基础。

Ammonia selective catalytic reduction technology is widely used in the elimination of nitrogen oxides in diesel vehicle exhaust due to its high efficiency, environmental protection, and low cost. The Cu/LTA zeolite catalyst with high silicon-to-aluminum ratio exhibits excellent hydrothermal stability and good catalytic performance in the NH3-SCR reaction, which points out a new direction for the study of lean nitrogen oxide catalytic reduction. However, low-temperature activity, by-product generation, and catalyst poisoning are still key issues that need to be resolved in the practical application of Cu/LTA catalysts. This project intends to effectively control the distribution of Cu active sites in the catalyst, study the influence of the key process parameters of catalyst preparation on the distribution of Cu active sites, and explore the correlation between the physical and chemical properties of the catalyst and its low-temperature catalytic performance, by-products, hydrothermal stability and poisoning mechanism; by analyzing the influence of the difference of catalytic active components on the catalytic reaction, the catalytic reaction path and catalytic active center of the reactants in different reaction stages are studied, and a variety of physical and chemical characterization methods and theoretical calculations are combined to infer the active center, O2 activation path and catalytic reaction mechanism in the low-temperature catalytic reaction process. This project provides an important experimental and theoretical research foundation for the key parameters of Cu/LTA catalytic material design and development.