强抗硫抗水中毒的锰基分子筛核壳结构低温脱硝催化剂构筑及机理研究

Low-temperature activity featured novel catalyst with strong resistance to poisoning has been a hot research issue in the field of selective catalytic reduction of nitrogen oxides at low temperature, which is also crucial for the development and application of low temperature NH3-SCR technologies. Hence, this project is to study controllable synthesis and structure control for NRS-MnOx@TS-1/M1-M2Ox zeolite core-shell low temperature SCR catalysts, resistance to sulfur dioxide and water vapour as well as the reaction mechanism. To be specific, manganese oxide nanorods as active component is the core, and a hydrophobic TS-1 molecular sieve thin layer is produced by microwave hydrothermal or other methods over the core, and the effects of core size, shell thickness, preparation methods on resistance to sulfur dioxide and water vapour as well as the low temperature SCR performance of the catalysts will be studied. The pore structure and aperture size of zeolite shell of catalysts will be regulated precisely by a chemical liquid deposition method, and then the screening effect of sulfur dioxide and anti-poisoning performance of the catalysts will be studied. Meanwhile, the fabrication of low temperature SCR catalysts with high activity as well as strong resistance to sulfur dioxide and water vapour are improved by molecular simulation calculation. Screening the elements of anti-sulfur and anti-water vapour poisoning by molecular simulation calculation is used for element doping. Combined with theoretical calculation and a variety of in situ characterization, zeolite core-shell catalysts' the low temperature SCR reaction mechanism and the mechanism of anti-poisoning will be revealed, which provides the technical support and theoretical guidance for designing and optimization of low temperature SCR catalysts with high activity and strong resistance to sulfur dioxide and water vapour.

强抗中毒、具有低温活性的新型催化剂是低温选择性催化还原(SCR)NOx领域的研究热点，也是低温NH3-SCR技术发展和应用的关键。本项目研究NRS-MnOx@TS-1/M1-M2Ox分子筛核壳结构低温脱硝催化剂的可控合成和结构控制、抗硫抗水性能及其催化作用机理。以活性组分锰氧化物纳米棒为核，通过微波水热等方法在内核上生成一层具有疏水性的TS-1分子筛薄层，研究内核尺寸、壳层厚度及合成方法等对催化剂低温SCR活性和抗中毒性能的影响；采用化学液相沉积法对催化剂壳层分子筛的孔径进行精准调控，研究催化剂壳层对SO2筛分效果及抗中毒性能的影响；通过分子模拟计算筛选抗硫抗水中毒的元素进行掺杂，构筑高活性强抗硫抗水性能的低温脱硝催化剂体系；结合理论计算和多种原位表征手段，揭示分子筛核壳结构催化剂的低温SCR反应机理和抗中毒机制，为强抗中毒、高活性低温SCR催化剂的设计和优化提供理论指导和技术支撑。

针对固定源低温SCR脱硝催化剂在含硫水烟气条件下易中毒失活问题，设计开发了具有核壳结构的强抗硫抗水性低温SCR脱硝催化剂体系(MnOx@Eu-CeOx和MnOx@S-1@FeOx等)。首先，采用FESEM、TEM、XRD、XPS、BET等对催化剂进行了构效关系研究，探索了制备参数等对所合成核壳材料的表面酸性、亲疏水性及低温脱硝性能和抗中毒能力的影响。其次，利用了理论计算手段构筑核壳结构模型后用于开发强抗中毒的低温SCR催化剂。最后，利用了多种原位表征手段研究核壳结构催化剂的低温SCR反应机理和抗中毒机制，并用于指导催化剂配方优化，在开拓新型低温抗中毒催化体系方面取得创新性成果。本项目的成功实施，为设计强抗中毒的低温SCR催化剂提供了新的研究思路和方法，同时为解决我们面临的大气污染问题提供理论和技术支撑，符合国家科技发展战略。通过本项目的资助申请了国家发明专利5项，其中3项已获授权，发表了6篇SCI论文和1篇CSCD论文，其中2篇环境类国际主流的杂志(IF>9)。总的IF=36.253，平均每篇文章的IF=6.04。这样25万元/6篇=4.17万元/篇，即每投资4.17万元可以获得科研成果为IF=6.04的SCI论文一篇。