烧结烟气低温脱硝多孔锰基复合物催化剂、反应机理及其应用研究

Worsening haze is the most serious environmental problems currently facing on China, and nitrogen oxides are one of the main pollutants causing haze. In the field of air pollution control, sintering flue gas denitrification is an urgent demand in China. Presently, selective catalytic reduction (SCR) is the most economical and reliable denitration technology. The traditional vanadium-based catalyst presents worse H2O and SO2 resistance and requires a higher active temperature (300~400 ℃), which cannot meet the low-temperature requirement for sintering flue gas denitrification (100~200 ℃). The project will combine porous materials, which possess large specific surface area, developed pore structure and good transfer properties for heat and mass, with manganese-based composite oxides with high low-temperature denitrification activity to build porous manganese-based composite oxide catalysts for higher denitrification activity and stronger H2O and SO2 resistance. It is expected to overcome the disadvantages of traditional catalysts. Furthermore, the project will deeply research the reactive processes at gas-solid interface and the inherent relationships between physical and chemical properties of materials and their performances by using in-situ analysis and advanced characterization methods, and reveal reaction mechanisms of denitration. Additionally, low-temperature denitration property of catalyst will be investigated in the simulation conditions of sintering flue gas to evaluate its prospects in industrial application. The results will provide new catalysts for low-temperature denitrification of sintering flue gas, provide a scientific basis for the preparation of a new generation of low-temperature denitration catalyst, and provide a new approach for the development of low-temperature denitration reactor with practical value. The important research value and significance are very obvious.

日趋严重的雾霾是目前我国面临的最严重的环境问题，氮氧化物是引起雾霾的主要污染物之一。烧结烟气脱硝是我国大气污染控制领域的迫切需求，选择性催化还原是目前最经济和可靠的脱硝技术。传统钒基催化剂抗湿抗硫性能差、所需反应温度高（300~400℃），不能满足烧结烟气脱硝的要求（100~200℃）。本项目针对传统催化剂的缺点，将多孔材料的大比表面积、发达孔隙结构和良好传热传质性能与锰基复合氧化物高的低温脱硝活性相结合，制备抗湿抗硫性能优异的多孔锰基复合氧化物催化剂；采用原位分析方法和先进表征手段研究反应气-固界面过程及材料物化特性与其脱硝性能的内在关联，揭示脱硝反应机理；在模拟烧结烟气工况下，研究催化剂低温脱硝性能，评价其工业化应用前景。研究结果将为烧结烟气低温脱硝提供新型催化剂，为制备新一代低温脱硝催化剂提供科学依据，为开发具有实际应用价值的低温脱硝反应装置提供新方法，具有重要的理论意义和实用价值。

日趋严重的雾霾是目前我国面临的最严重的环境问题，氮氧化物是引起雾霾的主要污染物之一。烧结烟气脱硝是我国大气污染控制领域的迫切需求，选择性催化还原是目前最经济和可靠的脱硝技术。传统钒基催化剂抗湿抗硫性能差、所需反应温度高（300~400℃），不能满足烧结烟气脱硝的要求（100~200℃）。本项目针对传统催化剂的缺点，将多孔材料的大比表面积、发达孔隙结构和良好传热传质性能与锰基复合氧化物高的低温脱硝活性相结合，制备了一系列多孔锰基复合氧化物催化剂，包括：多孔纯MnOx催化剂、具有核壳结构的锰铈复合氧化物中空微球、多孔MnM2O4 (M = Co, Cu, Ni)微球、多孔锰铁复合氧化物纳米针、稀土金属铕、钬掺杂改性的锰钛复合氧化物、以碳纳米管为模板制备得到的多孔锰钛复合氧化物以及锡掺杂的多孔锰钛复合氧化物等。并以NH3 为还原气体，对所制备的催化剂进行了选择性催化还原NOx的性能评价，考察了反应条件、烟气成分等因素对催化剂SCR脱硝性能的影响。采用多种分析表征手段，揭示了催化剂表面物理化学特性，阐明了其物化性质与其催化性能的内在关联。采用原位表征技术实时在线研究了气-固界面的作用过程及催化反应历程，揭示了多孔锰基复合氧化物低温SCR 脱硝反应机理。并在模拟烧结烟气工况下，研究了催化剂低温脱硝性能，评价其工业化应用前景。研究结果可为烧结烟气低温脱硝提供新型催化剂，为制备新一代低温脱硝催化剂提供科学依据，为开发具有实际应用价值的低温脱硝反应装置提供新方法，具有重要的理论意义和实用价值。