鈣鈦礦型復(fù)合氧化物催化消除NO的研究.pdf

1、Nitrogen oxides (NOX) are serious pollutants in earth s atmosphere, they are harmful gases both to environment and human body. As one catalyst for NOX removal, special attention has been paid to the use of perovskite mix

2、ed oxides due to their remarkable stability, and perovskite-type oxides can accommodate a large number of metal, which result inthe obtained samples possessing special character. In this dissertation, a series of perov

3、skite-type oxides via substituting the A or B site of LaFeOa and LaMnOa were successfully synthesized through citric acid complexing sol-gel method. The influence of doping elements in A site and B site and the doping ra

4、tio on the catalytic activity of perovskite-type oxides was also discussed in this thesis. It was found that the activity in NO direct decomposition could be improved by substituting alkaline-earth metals for La, in whic

5、h the samples of substituting Ba for La performed best activity. XRD results demonstrated that perovskite phase is retained at low 20％ Ba doping content, H2 temperature programmed reduction (H2-TPR) indicate that low sub

6、stituting Ba for La performed their activity for NO removal through enhancing the oxidability of B site metal. The conversion of 1.0％ NO to nitrogen over La0.75Ba0.25FeO3 can attain 72％ at 850℃. The influence of doping e

7、lements in B site was also discussed in this thesis. It was found that doping Fe and Mn series catalysts performed special catalytic activity. H2-TPR and O2 temperature programmed desorption (O2-TPD) indicate that B site

8、 doping different transition metal can enhance the oxidability of B site metal, increase the amount of oxygen vacancy and promote the mobility of crystal lattice oxygen. The conversion of 1.0％ NO to nitrogen is 88％ and 9