高能结构纳米粒子/氧化铝的封装构筑及其脱VOCs催化性能研究

During the removal process of VOCs by catalysis oxidation, agglomeration, sintering, and many kinds of structures of the active species often occur since high temperature conditions are often employed in the catalyst preparation and using process for the tradition catalysts. Obviously, the complicated compose is not beneficial to obtain an accurate structure-activity relationship and to design a catalyst with excellent performance. To solve this question, a notion was built for preparing the catalyst with high activity and high stability, which will be carried out by preparing the monodispersed nanoparticles with high surface energy and then encapsulating them with protective structure. To enhance the catalytic activity, based on kinetically controlled synthesis, a series of monodispersed oxides nanoparticles with high surface energy of Mn, Cu, W, and Fe will be prepared through modulating the size and the crystalline structure. To increase their stability, based on directed assembling and layer-by-layer encapsulation, the nanoparticles will be protected by encapsulation. Moreover, to ensure the mass transfer, thermal diffusion, and avoid poisoning, more attentions will be paid to design the geometrical structure and electronic structure of the alumina encapsulation layers. Subsequently, the influencing law of the structures of the nanoparticles and the encapsulation layers on the catalytic activity and stability, and the relative catalysis mechanism will be also explored. Based on these studies, the structure-activity relationship model about the catalysis reaction of VOCs removal will be established, which is expected to provide a new catalyst for achieving the deep decontamination of VOCs and to offer an idea for preparing a new catalyst with high activity and high stability.

在VOCs催化氧化治理中，催化剂制备及其使用过程的高温条件，常致使活性组分团聚烧结、多种结构共存，这一复杂组成显然不利于其构效关系的准确量化及高性能催化剂的设计。针对这一问题，本项目提出制备单分散高能结构活性纳米粒子并对其进行稳定化封装，构筑高活性、高稳定性脱VOCs催化剂的设想。基于动力学生长控制技术，调变纳米粒子的尺寸和晶型结构，实现系列单分散高能结构Mn、Cu、W和Fe等氧化物纳米粒子的制备，以此提高催化活性；在此基础上，借助定向组装和层层封装技术，对所合成的高能纳米粒子进行封装保护，并重点调控氧化铝封装涂层的几何结构和电子结构分布，确保催化剂的热、质扩散和抗毒能力，以此提高催化稳定性。探索性研究高能纳米粒子及封装涂层的结构对催化活性和稳定性的影响规律及相关催化机理，建立构效关系模型，力求为VOCs的深度净化贡献新型高效催化材料，研究成果也将为高活性、高稳定性催化剂的设计提供新思路。

为深度脱除挥发性有机化合物，获得高活性高稳定性催化材料的客观要求，本项目从制备单分散高能结构活性纳米粒子并对其进行稳定化封装出发，构筑高活性、高稳定性脱VOCs催化材料。通过动力学生长调控，发展了金属离子诱导、液/固水热还原等动力学调控生长法，实现了系列Cu、Fe、Mn等高能结构氧化物微/纳米粒子的制备和晶面调变；同时为获得具有良好的传质、传热效果的多孔结构，在Al2O3、SiO2、TiO2、LaMnO3等封装组分的结构调控中进行了深入研究。系统研究了大孔、介孔和微孔的成孔规律及其对比表面、催化传质过程的影响；深入考察了活性粒子的尺寸、晶型等结构对催化活性的影响规律。研究显示活性组分的晶面结构、价态、化学组成等因素对催化性能具有决定性的影响。研究成果为该类催化剂的设计提供了新思路。发表学术论文26篇，其中SCI收录论文21篇；申请发明专利7项，其中已获授权发明专利4项。