A novel four-way combining catalysts for simultaneous removal of exhaust pollutants from diesel engine

• Published in: Journal of environmental sciences (China) 2010-07, Vol.22 (7), p.1104-1109
• Main Authors: Liu, Jian, Xu, Jie, Zhao, Zhen, Duan, Aijun, Jiang, Guiyuan, Jing, Yanni
• Format: Article
• Language: English
• Subjects: Air Pollutants - chemistry; Calcium Compounds - chemistry; Catalysis; Catalysts; Conversion; diesel engine exhaust; Diesel engines; Double layer; double layers; Exhaust; four-way combining catalyst; Microscopy, Electron, Scanning; Oxides - chemistry; perovskite oxides; Pollutants; Scanning electron microscopy; Titanium - chemistry; Vehicle Emissions; zeolite catalysts; Zeolites - chemistry; 催化剂; 扫描电子显微镜; 排气污染物; 柴油发动机; 漫反射光谱; 紫外可见; 转化温度
• ISSN: 1001-0742; 1878-7320
• DOI: 10.1016/S1001-0742(09)60224-2

A novel four-way combining catalysts containing double layers was applied to simultaneously remove four kinds of exhaust pollutants （NOx, CO, HC and PM） emitted from diesel engine. The four-way catalysts were characterized using scanning electron microscope （SEM） and Ultraviolet visible diffuse reflectance spectroscopy （UV-Vis DRS）. Their catalytic performances were evaluated by temperature-programmed reaction technology. The double layer catalysts could effectively remove the four main pollutants. The highest catalytic activity was given by the two-layered catalysts of La0.6 K0.4CoO3/Al2O3 and W/HZSM-5. Under the simulated exhaust gases conditions, the peak temperature of the soot combustion was 421℃, the maximal conversion of NO to N2 was 74%, the temperature of the HC total conversion was 357℃, and the maximum conversion ratio of CO was 99%.