双壳层Pt纳米催化剂可控构筑及其催化氧化去除甲苯和氯苯性能

Catalytic oxidation is one of the most promising technologies for removal of volatile organic compounds (VOCs). The urgent problem to be solved is the synchronous removal of multicomponent with different physicochemical properties on the way to industrialization. In the present proposal, a core/dual-shell Pt@TiO2@Mn-X-O (X = Ce、La、Cu) catalyst is fabricated with Pt nanoparticles (NPs) as core, TiO2 as inner shell, and Mn-X-O as outer shell, which coupled with the low-temperature catalytic activity of Pt NPs and the resistance to Cl species of Mn composite oxide with the aim to synchronous catalytic oxidation of the representative of VOCs such as methylbenzene (MB) and chlorobenzene (CB). The influences of microstructure, particle size, redox ability, and surface acidity of the core/dual-shell catalyst on the catalytic activity and resistance to Cl species will be investigated systematically. Furthermore, the function of active component during the catalytic oxidation process of MB and CB will be clarified. Besides, the competition mechanism of MB and CB on active sites will be proposed. Additionally, based on the formation of intermediates and products and kinetic theory calculation, removal efficiency and mechanism of the present bi-VOCs will be revealed, having theoretical implications for catalyst design and industrial catalytic oxidation of multicomponent VOCs.

催化氧化法是挥发性有机物(VOCs)去除的主流技术之一，多组分VOCs的联合去除是其工业化的瓶颈。本项目拟耦合Pt的低温活性和Mn基复合氧化物的抗氯性能，以Pt纳米粒子为核，TiO2为内壳，Mn基复合氧化物为外壳，构筑Pt@TiO2@Mn-X-O (X = Ce、La、Cu)双壳层催化剂。以甲苯和氯苯为探针分子，系统研究催化剂微观结构、颗粒尺寸、氧化还原性能、表面酸性等与其低温活性和抗氯性能之间的关系，探究甲苯和氯苯在活性位点的竞争关系，阐明活性组分在联合催化氧化去除甲苯和氯苯中的作用。结合反应中间体、过渡态和产物以及反应动力学研究，揭示双壳层Pt纳米催化剂去除甲苯和氯苯的机制，为多组分VOCs废气净化技术的发展奠定坚实基础。

本项目采用催化氧化技术，以催化活性和稳定性能为导向设计合成多功能催化剂体系，用于复杂工业尾气中甲苯和氯苯的高效净化。主要内容如下：（1）通过原位方法构建Co3O4-MnO2、CuO-MnO2异质界面，研究了界面效应对催化剂表面物理化学性质的影响，明晰界面效应对催化性能的影响，探讨了甲苯在界面处的氧化分解机理；（2）通过原位氧化还原方法构建了空心结构CuMnOx及核壳结构Au@CuMnO2催化剂，研究空心及核壳结构催化剂催化氧化VOCs性能的影响因素及催化氧化机理；（3）提出一种简单方法合成形貌可控、反应晶面选择性暴露的三维自组装Co3O4微球催化剂，探索不同暴露晶面对催化活性的影响机制；（4）探讨了不同金属氧化物掺杂对Mn基和Co基氧化物催化氧化甲苯性能的影响，提出了种类、掺杂量及制备方法对催化氧化活性的影响机制（5）通过HSiW调变CeO2基催化剂的酸性和氧化还原性能，构建双活性位点并探讨催化氧化氯苯性能及机制，研究了制备方法、Pt的担载量、价态对氧化还原能力及酸性的影响，并探讨了双活性位点的功能及催化氧化氯苯的机理。本项目解决了相关科学问题，从理论指导实践，为工业废气多组分VOCs废气治理发展方向提供新思路。发表收录文章27篇，申请专利3项，撰写专著1部。