SiO2精细化调控SCR脱硝催化剂微观结构及其高效抗硫机理研究

燃煤烟气低温脱硝反应中硫中毒导致的催化剂失效是制约燃煤电厂深度调峰的关键难题，宽温区抗硫高效催化理论方法是燃煤机组全负荷超低排放亟待解决的科学问题。催化剂改性是研究热点，但低温下ABS沉积与活性组分硫酸化等SO2中毒机理与抗中毒方法仍未解决。本项目聚焦于催化剂微观结构调控提高抗硫性能，采用SiO2调控TiO2载体微观结构，解耦催化剂孔道内脱硝与SO2氧化反应中扩散-反应过程与ABS沉积分解过程交互作用，解析催化剂微观结构与抗硫活性关联特性；结合实验表征与量子化计算研究SiO2与TiO2相互作用机理，揭示活性组分与复合载体相互作用机制，指导复合载体表面活性组分优化负载，创新实现催化剂微观结构与化学特性协同调控；优化V-W-Mn-Ce/TiO2-SiO2催化剂，揭示催化剂高效抗硫机理，实现催化剂宽温区高效脱硝。本项目为催化剂结构设计、优化提供科学依据，为燃煤机组宽负荷脱硝提供理论和技术基础。

The deactivation of catalyst, caused by sulfur poisoning in the low-temperature denitration reaction of coal-fired flue gas, is a key problem that restricts the deep peak shaving of coal-fired power plants. The theoretical and method of anti-sulfur poisoning and high-efficiency catalysis in a wide temperature range is a scientific problem that needs to be solved urgently for ultra-low emissions at full load of coal-fired units. Catalyst modification is a research hotspot, but the SO2 poisoning mechanism such as ABS deposition and active component sulfation at low temperature, and anti-sulfur poisoning methods have not been solved yet. This project focuses on the adjustment of the catalyst microstructure to improve the sulfur resistance, using SiO2 to adjust the microstructure of the TiO2 support, decouples the interaction between the diffusion-reaction process, during the denitration and SO2 oxidation reaction process, and the ABS deposition and decomposition process in the catalyst pores, and analyzes the correlation characteristics of catalyst microstructure and anti-sulfur activity; Then combining with the experimental characterization and quantum chemistry calculation to study the interaction mechanism of SiO2 and TiO2, the interaction mechanism of active components and composite supports is revealed, and guides the optimization of active components loading on TiO2- SiO2 complex supports, and innovatively realizes the coordinated control of catalyst microstructure and chemical characteristics; Optimizing the V-W-Mn-Ce/TiO2-SiO2 catalysts, studies the catalyst's high-efficiency anti-sulfur mechanism, and finally to achieve the high denitration efficiency of the catalyst in a wide temperature range. This project will provide a scientific basis for the design and optimization of the catalyst structure, and a theoretical and technical basis for efficient denitrification of coal-fired units under wide-load.