三维大孔微纳结构的金属氧化物负载单原子贵金属整体式碳烟燃烧催化剂

Soot particulate emitted from diesel engines is one of the major sources for air pollution of PM2.5. Nowadays, the effective technology for the elimination of the soot pollutants is to capture soot via the diesel particulate filter (DPF), and then catalyze the soot combustion by the powder catalysts sprayed on the DPF. This project aims to in situ construct three dimensional macroporous nano-structured metal oxide catalysts on the DPF substrate, and then load the single-atom noble metal component thereon. The optimization of the pretreatment conditions upon the monolithic catalysts is employed to control the interaction between the single-atom noble metal and the metal oxide support, thus improving the activity and the thermal stability of the catalysts. In addition, the project also investigates the dispersion states, the local coordination environments, and the surface electronic structures of single-atom noble metals, and the generation and activation of active oxygen species through characterizations of high-resolution electron microscopy, in situ spectroscopy and temperature-programmed techniques, thus clarifying the reaction mechanism of catalytic soot combustion. Compared with the traditional catalysts, the single-atom noble metal monolithic catalyst developed in this project can significantly increase the soot-catalyst contact efficiency and greatly reduce the cost of noble metals. The successful implementation of this project will provide a new approach to removal of soot pollutants for the diesel engines, promote the development of the automotive industry, and protect our environment. Therefore, it has both the important scientific significance and the application prospect.

柴油发动机所排放的碳烟颗粒是大气污染物PM2.5的主要来源之一，目前主要通过在颗粒过滤捕集器（DPF）上喷涂粉体催化剂，利用催化燃烧将所捕集的碳烟颗粒催化消除。本项目拟在DPF基底上原位构建三维大孔微纳结构的金属氧化物材料，然后在其上负载单原子贵金属组分用于碳烟催化燃烧。通过调变催化剂预处理条件，精准调控单原子贵金属与金属氧化物载体间的相互作用，以期提高催化剂的活性和热稳定性。此外，本项目还通过高分辨电镜测试、原位光谱学实验和程序升温技术等手段，考察单原子贵金属活性中心的分散状态、微观局域配位环境、表面电子结构等信息，以及活性氧物种的产生和活化机制，阐明碳烟催化燃烧反应机理。与传统催化剂相比，本项目研发的单原子贵金属整体式催化剂能够显著提高碳烟与催化剂接触几率，大幅度降低贵金属使用量，为柴油发动机尾气净化技术提供新的理论方法，促进我国汽车和环保产业的发展，具有重要的科学意义和应用前景。

柴油发动机所排放的碳烟颗粒是大气污染物PM2.5的主要来源之一，目前主要通过在颗粒过滤捕集器（DPF）上喷涂粉体催化剂，利用催化燃烧将所捕集的碳烟颗粒催化消除。本项目提出在DPF基底上原位构建三维大孔微纳结构的金属氧化物材料，然后在其上负载低含量贵金属，并通过设计金属氧化物的纳米形貌（如：纳米棒、纳米线、纳米片、纳米花等），调控金属氧化物上的氧缺陷、暴露晶面以及金属与金属氧化物之间的界面相互作用，进一步开发出兼具高活性和稳定性的整体式碳烟燃烧催化剂。此外，还通过高分辨电镜测试、原位光谱学实验和程序升温技术等手段，考察金属活性中心的分散状态、微观局域配位环境、表面电子结构等信息；通过同位素实验和动力学研究，总结活性氧物种的产生和活化机制，阐明碳烟催化燃烧反应机理。与传统催化剂相比，本项目研发的整体式催化剂能够显著提高碳烟与催化剂接触几率，大幅度降低贵金属使用量，为柴油发动机尾气净化技术提供新的理论方法，促进我国汽车和环保产业的发展，具有重要的科学意义和应用前景。