不同条件对钙钛矿型BaZrO3储存NOx的影响

采用改进的柠檬酸络合溶胶-凝胶法制备了钙钛矿型BaZrO3催化剂, 考察了焙烧温度, 吸附温度及SO2浓度对BaZrO3样品富氧条件下的NOx储存性能(NSC)的影响; 对其储存的NOx进行了程序升温脱附(TPD-MS)测试, 并用BET比表面测定(SA), X射线衍射(XRD)等方法研究了催化剂的结构及其对性能的影响. 结果表明, 750℃下焙烧的BaZrO3具有相当高的比表面(84.0 m2/g), 而900 ℃下焙烧的BaZrO3样品烧结程度较高, BaZrO3是主要的NOx吸附中心, BaZrO3-750 ℃的NSC高于BaZrO3-900 ℃. BaZrO3样品储存NOx的最佳温度应该在400 ℃左右.

NOx Storage of BaZrO3 Affected by Different Conditions

perovskite-type BaZrO3 catalysts were prepared by sol-gel method. The effect of calcination temperature, adsorption temperature and the SO2 concentration on NOx storage capacity (NSC) of BaZrO3 were investigated. Temperature-programmed desorption (TPD) of adsorbed NOx was also measured. BET surface area and X-ray diffraction (XRD) techniques were also used to characterize their structure and the influence of the structure on performance. The results indicate that, BaZrO3 calcinated at 750 ℃ possesses quite higher BET surface area (84.0 m2/g) than that calcinated at 900 ℃. The NSC of BaZrO3 calcinated at 750 ℃ is also higher than that of BaZrO3 calcinated at 900 ℃. It implies that BaZrO3 is the main NOx adsorbed center. The optimum temperature for NOx storage of BaZrO3 is 400 ℃ or so.