消除碳烟污染的非化学计量氧陶瓷过滤器的催化燃烧机理

2013年初以来，我国多次遭受严重的灰霾（PM2.5）侵袭，其中柴油车排放的碳烟颗粒是重要的污染源。安装颗粒过滤器(DPF)是最有效的碳烟控制技术，但是DPF必须通过催化燃烧再生。由于尾气中比氧气活性高的NO2浓度低，又是另一种需要控制的污染物，因此DPF应立足于氧气本身的活性。该项目将具有催化作用的非化学计量氧陶瓷材料制作成DPF过滤器，而不仅仅作为催化剂涂覆在DPF载体上。这样既发挥了捕集碳烟的作用，又解决了涂覆式催化剂与碳烟的接触不良、堵塞DPF孔道、热稳定性差和流失等问题。项目将抓住非化学计量氧在碳烟燃烧中所起的作用这一关键科学问题，建立动态储/放氧性能与活性的关系，重点利用O18同位素和在反应条件下的原位技术揭示碳烟燃烧的机理，并将优选材料压制成陶瓷过滤膜，验证实际捕集和催化燃烧效果。项目将提供从材料、机理到器件的碳烟治理前沿技术，从源头上解决柴油车排放的PM2.5问题。

Since 2013, China has suffered severe haze (PM2.5) invasion. Therein, soot particulates from diesel engines are important sources of PM2.5. The application of a Diesel Particulate Filter (DPF) is the most effective control technology for diesel soot emissions. However, DPFs must be regenerated by catalytic combustion. Because NO2 which can oxidize soot at lower temperatures than O2, has a low concentration in diesel exhaust and NOx is another pollutant which must be treated, the oxdiation of soot by O2 is crucial. In this project, nonstoichiometric oxygen ceramic materials were selected to elaborate a DPF, rather than only washcoated on a supporter. This can not only capture soot but also provide sufficient contact points with the soot particles, and can avoid blocking of filter pores, sintering and elution of catalysts. Focused on the role of nonstoichiometric oxygen in catalytic soot combustion, the key problem of the project, the relationship between dynamic O2 storage/release properties and activity will be constructed. Furthermore, the mechanism based on O18 isotopic and in situ/operando experiments will be elucidated. Finally, the porous membranes will be developed to simulate the porous walls of DPFs. Their filtering and catalytic properties will be investigated in quasi real conditions. The project will provide advanced technologies for soot emission control, including materials, mechanism and filters, in order to resolve the PM2.5 problem from diesel soot emissions at its source.