Study On Catalytic And Antideactivation Properties Of La-Ba-Cu-O For Purification Of Automobile's Exhaust

Perovskte-type oxides have attracted particularly attentions because of their special applications as functional materials. According to the reported literatures and analysing the researsh and the development of the perovskite-type compound oxides, choose perovskte-type oxides as disquisitive object, research their preparation and properties, provide academic and experimental data for automobile's exhaust catalytic instrument.A series of layered perovskite-type compound oxides were synthesized by citrate acid sol-gel method,adulterated A, B-site with different metal ions(A-site with Sr, Ce, B-site with Ni, Fe), the physicochemcal properties and function mechanism of the materials were characterized by means of XRD, SEM, BET, TPD, considered the affected factor of the catalytic activity such as differern calcined temperature, A, B-site adulteration,tested the catalytic activity with CO, CH₄ and anti-sulfuration, associated the characters with their physicochemcal properties.The XRD spectrum demonstrated that at the calcined tempereture 900℃, the perovskte-type phase is simple, when the calcined tempereture was 750℃, some foreign matter phases apper.The SEM test indicateed the particle size increase with the calcined temperature increases. The BET test results indicate the specific surface area of the materials increase when the quantity of doping Ni, Fe in the B-site is low, when the quantity is high, the specific suefece area could descend.the doping Ce, Sr in A-site reduce the specific suefece area. TPD results show that the concentration of oxygen at the sueface is associated with catalytic activity.The catalytic activity decrease with the calcined temperature increases, but it increase when the quantity of doping Ni, Fe is appropriate,then decrease when the doping is excessive.among these materials, La₄BaCu₂Ni₃0_13+δ, La₄BaCu₂Fe₃O_13+δ have the best catalytic activity,between the two, La₄BaCu₂Fe₃O_13+δ is better.The sulfuration results show the doping Ni, Fe increase the anti-sulfuration, SO₂ make the structure disaggregate, XRD spectrum show CuSO₄ appers firstly, then the appear of BaSO₄ makes the structure disaggregate.