Fe改性MnOx/TiO2催化剂脱硝协同氧化Hg0的抗硫氧化物中毒机制研究

燃煤汞排放控制是当前我国生态环境保护战略的重要组成部分，采用MnOx/TiO2中低温SCR催化剂脱硝协同氧化脱除烟气中的Hg0是一种具有良好应用前景的汞减排方式。本项目针对MnOx/TiO2催化剂在抗硫性上存在的不足以及Fe改性对其抗硫性产生的改善效果，采用实验研究与理论计算相结合的方法，探究催化剂的SO2中毒失活机制、SO3对催化剂汞氧化效率的影响规律、以及富氧燃烧烟气下催化剂的抗硫性；分析在改性后催化剂上，Fe元素在硫氧化物参与的反应过程中所起的催化作用。深入揭示燃煤烟气中的硫氧化物对MnOx/TiO2脱硝协同汞氧化活性的影响机制，阐明Fe对催化剂在不同烟气下抗硫性的改性机制，掌握决定催化剂抗硫中毒性能的关键因素，形成“催化剂构型-烟气工况-抗硫性”的理论体系。项目的研究成果可为提高MnOx/TiO2在燃煤烟气下的抗硫性，实现其在中低温下脱硝协同脱汞的商业化应用提供科学依据与技术支撑。

Control of mercury emissions from coal combustion is an important part of the ecological environment protection strategy of China. Utilizing the medium-low temperature SCR catalyst of MnOx/TiO2 to oxidize elemental mercury in coal combustion flue gas synergistically while removing NO is a Hg emission reduction approach with bright application prospects. This project aims at the defect of the MnOx/TiO2 catalyst in sulfur resistance and the improvement effect on the sulfur resistance by Fe modification. Through the research method of combining experiment and theoretical calculation, the poisoned inactivation mechanism of SO2 on the MnOx/TiO2 catalyst, influence rule of SO3 on Hg0 oxidation efficiency of the catalyst, and the sulfur resistance of the catalyst under oxy-fuel combustion flue gas will be explored. On the modified catalyst, the catalysis of element Fe in the reaction process with sulfur oxides participating will be analyzed. As a result, the influencing mechanisms of sulfur oxides on the NO removal and synergistic Hg0 oxidation activity of MnOx/TiO2 will be revealed in depth. The modification mechanisms of Fe on the sulfur resistance of the catalyst in different flue gases will be clarified. The key determining factors of the modification effect of Fe on the sulfur tolerance will be grasped. A theoretical system of “catalyst configuration - flue gas condition - sulfur resistance” will be formed. The research achievements of the project will supply scientific basis and technical support for improving the sulfur resistance of the MnOx/TiO2 catalyst under coal-fired flue gases, thereby realizing the commercial application of the catalyst for NO and synergistic Hg removal in the condition of medium-low temperature.