有机-无机杂化调控负载TNU-9低温高效脱硝催化剂

Concerned with problems of active sites uneven distribution and easier deactivation of the denitration catalyst in H2O and SO2, the efficient low temperature denitration catalyst is prepared by organic-inorganic hybrid means. Active sites distribution in the periodic microporous silicon oxide (TNU-9) pore channels is effectively controlled by the assembly technique of template and the collaborative assembly technique of template and silicon species. It explores the association relationship between preparation conditions and distribution of active sites in catalyst, clarifies the internal laws between the loading of active components and the hydrolytic rate of silica source, and reveals the influence of distribution of the active sites and coordination environment on the denitration performance. To improve the sulfur dioxide and water resistance, the project intends to control of surface acidity and hydrophilic/hydrophobic performance of catalysts. It illuminates the mechanism of the catalyst denitration and anti-inactivation. Implementation of this project would provide new ideas and method for develop the efficient low temperature denitration catalyst and is beneficial to explore the mechanism of the denitration reaction and anti-inactivation. It may make a breakthrough in the field of air pollution control. Meanwhile it is of great significance in even dispersion law of active sites distribution in the support pore channels.

针对脱硝催化剂活性中心分布不均及在H2O和SO2环境下易失活等问题，采用有机-无机杂化手段，通过模板剂自主装和模板剂与硅物种的协同组装技术，调控催化剂活性中心（Cu和Ce）在周期性微孔分子筛（TNU-9）孔道中的分布，制备低温高效脱硝催化剂。探索制备条件与催化剂活性中心分布的关联关系，明晰硅源水解速度与活性组分负载量之间的内在规律，揭示催化剂活性位落位情况和配位环境等对脱硝性能的影响。通过调控催化剂表面酸性及表面亲水/疏水特性，提高脱硝催化剂在SO2环境下的稳定性和抗水性，阐明脱硝和抗失活机理。本项目的开展为开发低温高效脱硝催化剂提供了新思路和新方法，有助于深入探究脱硝反应和抗失活机理，有望在大气污染物治理领域取得突破，同时，对于揭示催化剂活性中心在载体孔道中的均匀分散规律具有重要的科学意义。

以NH3为还原剂的选择性催化还原（NH3-SCR）是最重要的脱硝方法之一，高温脱硝相对成熟而低温脱硝仍不理想，而催化剂是低温脱硝的灵魂，低温脱硝催化剂受H2O和SO2的影响，活性明显下降。针对脱硝催化剂活性中心的分布不均及在H2O和SO2条件下易失活等问题，本课题组在三年的时间里，对活性中心为过渡金属（Cu、Co、Ce、Mn等）催化剂的构筑、脱硝性能及抗失活机理研究开展了比较系统的工作。对催化剂活性中心的分布进行了调控，制备了多种低温高效脱硝催化剂。考查了不同反应条件对脱硝催化剂的影响，总结实验规律，优化实验过程，提高了催化剂的脱硝性能和在H2O和SO2环境下的稳定性。此外，深入研究了催化剂在不同温度和SO2和H2O存在下在NH3-SCR反应中的催化性能及催化剂抗失活的机理。结合X射线光电子能谱（XPS）、NH3程序升温脱附（NH3-TPD）和H2程序升温还原（H2-TPR）等表征手段阐明了提高脱硝催化剂性能的原因，明晰脱硝催化剂抗失活机理。本项目研究成果为开发低温高效脱硝催化剂提供了理论依据和新思路，有望为烟气脱硝的实际应用提供新想法，有助于深入探究脱硝反应机理和抗失活机理。此外，同时，对于揭示催化剂活性中心均匀分散规律具有重要的科学意义。