【摘要】 采用低温燃烧法制备了Ce4+部分取代La3+的La1-xCexCoO3系钙钛矿型复合氧化物催化剂,用XRD、TGA、SEM和化学分析等方法对催化剂的组成、结构等进行了表征。利用程序升温反应(TPR)技术,对催化剂应用于柴油机常规排放物中的微粒(PM)、碳氢化合物(THC)、氮氧化合物(NOx)的催化脱除性能进行了研究。结果表明,Ce4+部分取代La3+,催化剂表面氧空位浓度增加,同时形成Co3+-Co2+共存体系,催化剂对THC、NOx催化活性显著提高,且稳定性良好。但Ce4+的掺杂并没有提高催化剂对PM的催化活性。更多还原

【Abstract】 A series of complex oxide La_1-xCe_xCoO₃ catalysts were synthesized at low temperature through a combustion process,in which x is among 0,0.1,0.2,0.4 and 0.6 corresponding to the quantity of La³⁺ partial substitution by Ce⁴⁺.And the catalysts were characterized for phase composition using chemical analysis and x-ray diffraction.The surface characterization of the catalysts was determined by SEM.The catalytic activity of the catalysts in removal of NO_x,THC and particulate matter（PM） from diesel exhaust gases were examined in details using temperature-programmed reaction（TPR） technique.The results show that after partial substitution of La³⁺ with Ce⁴⁺ the oxygen vacancy concentration increases significantly and Co³⁺-Co²⁺ system is formed,and consequently the catalytic activity in removal of THC and NO_x is significantly improved.But for PM,the effect is not so obvious,and the possible catalytic mechanism was also presented.The doped catalysts also show good stability.更多还原