Study On Structure And Electrical Conductivity And Catalytic Properties Over La_1-xSr_xCoO₃ Perovskite-type Compounds

Sulfur dioxide is one of the main pollutants in the atmosphere. It is essential to put more efforts to flue gas desulphurization (FGD). Flue gas desulphurization through catalytic reduction means reduction of sulfur dioxide in flue gas to elemental sulfur through catalytic reaction over some kind of catalyst. Recently this field is drawing more and more attention.ABO3 perovskite-type compound is an excellent catalyst for the reduction of sulfur dioxide by carbon monoxide, moreover it displays good electrical properties. In this paper a series of composite oxides La1-xSrxCoO3-δ(x=0,0.1,0.2,0.3,0.4) were prepared by citrate method. Electrical conductivity was measured and compared at different temperatures under gaseous atmosphere such as O2,CO,SO2 and so on. The catalytic activity on the reduction of SO2 by CO was analyzed before and after activation-sulfurization.The research results show that oxygen vacancy increases in virtue of adulteration and oxygen distribution varies in La1-xSrxCoO3-δwhich is p-type semiconductor. The conductivity increases with Strontium content. Diverse gaseous atmosphere makes different effect on conductivity but it can not change the regularity of conductivity after Strontium doped. In addition the adsorption of CO is stronger than that of SO2. The perovskite structure is completely destroyed and new sulfides are formed after sulfurization. Based on this condition the conductivity and adsorption ability of SO2 clearly become lower whereas the pattern of conduction still keeps to invariability. The content of S2- in samples exhibits significant impact on catalytic properties, moreover adsorptive function of SO2 may be a critical factor.