Frontiers of Chemical Science and Engineering
Properties of La1-xCexCoO3 system perovskite-type catalysts for diesel engine exhaust removal
1.School of Material Science and Engineering, Tianjin University, Tianjin 300072, China; 2.Key Laboratory of Engine, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China;
Available online: 2007-03-05
A series of complex oxide LaCeCoO catalysts was synthesized at a 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 La partial substitution by Ce. The catalysts were characterized for phase composition using chemical analysis and X-ray diffraction. The catalytic activity of the catalysts in removal of NO, total hydrocarbon (THC) and particulate matter (PM) from diesel exhaust gases were examined in detail using temperature-programmed reaction technique. The results show that after partial substitution of La with Ce, the oxygen vacancy concentration increases significantly and a Co-Co system is formed. Consequently, the catalytic activity in the removal of THC and NO is significantly improved. But for the PM, the effect is not so obvious. The possible catalytic mechanism for this was presented. It is also worth noting that the doped catalysts showed good stability.