ABO2型复合氧化物上CO-NO的反应性能

以柠檬酸络合法制备了CuCrO2、CuAlO2和CuFeO2等具有铜铁矿结构的ABO2型复合氧化物,并考察了它们在氧化和还原气氛中对CO NO反应的影响. CuAlO2和CuCrO2具有好的催化活性, CuCrO2更具有相当的稳定性,经过氧化和还原条件下的CO NO反应后,体相组成仍然保持不变. CuAlO2在还原条件下,部分被还原生成了零价铜. CuFeO2的催化活性和稳定性较差,在还原气氛中催化CO NO反应过程中,样品被还原,完全转化成了Cu0和CuFe2O4.

CO-NO Reaction over ABO2 Complex Oxides with Dalofossite Structure

ABO2(A=Cu; B=Cr,Al,Fe) complex oxides have been prepared by amorphous citrate precursors method. Formation of single phase dalofossite structure was confirmed by XRD examination. A conventional fixed-bed micro-reaction technique was used in measuring the catalytic activities of these complex oxides for CO NO reaction under both oxidizing and reducing conditions. CuAlO2 and CuCrO2 show good catalytic activity towards CO NO reaction. CuCrO2 was quite stable and no changes in the bulk phase composition were detected even after long time CO NO reaction under both oxidizing and reducing conditions. CuAlO2, which was stable enough under oxidizing conditions, was partly reduced to Cu0 after long time catalytic reaction under reducing conditions. Although no phase composition chan ges were detected in CuFeO2 bulk phase after long time catalytic test under oxidizing conditions, partial reduction on the surface can be expected. After catalytic test under reducing conditions, CuFeO2 totally converted to Cu0 and CuFe2O4.Compared with those catalysts of perovskite structure, ABO2 samples show much better catalytic activity for CO NO reaction.