Fabrication Of SiOC/La_0.9 Sr_0.1 CoO₃ Catalysts By Fibrous Template And The Catalytic Activity For Diesel Engine Exhaust Purification

The pollution of diesel engine exhaust has become the focus that people pay attention to increasingly with the diesel engine being widely used as automobile power, and the governments around the world unveil a series of regulations to limit the emission of diesel engine. Aftertreatment technology for diesel engine exhaust is playing an irreplaceable role on satisfying the request of low emission. Focusing on the removal of NOx and PM, we successively obtained the SiOC/La0.9Sr0.1CoO3 catalysts which can simultaneously remove both of NOx and PM on the foundation of preparation of perovskite catalyst. The research works in this paper are summarized as follow:(1)Two kinds of precursor fibers were prepared by sol-gel/electrospinning technology and sol-gel/impregnation method respectively with PVP and glucose as chelating agent, and the optimum conditions to get gel fibers were defined.(2) Perovskite (La0.9Sr0.1CoO3) catalyst was gained with the crystallites size 100 nm by the heat treatment process for gel fibers of La0.9Sr0.1CoO3. It showed that the perovskite structure emerged after calcination at 700℃in air. When the calcination temperature was up to 800℃, it completely transformed to perovskite structure.(3)The SiOC/La0.9Sr0.1CoO3 catalysts with channel structure on whose inner surface found the Lao.9Sr0.1CoO3 crystal were produced by gel and polyester fiber template method. It was proved that both kinds of fibers played the role of making channels and transformed to the La0.9Sr0.1CoO3crystal finally.(4)It was found that both of the increase of calcination temperature and tempering treatment in air could improve the catalytic activity of catalytic filter. The maximum NOx conversion of SiOC/Lao.9Sr0.1CoO3 catalysts prepared by gel and polyester fiber template method was 29.8% and 25.9% respectively.