Cu-Mn氧化物催化N_2O直接分解性能

Catalytic decomposition of N_2O over Cu-Mn oxide catalysts

分别以Cu(NO_3)_2·3H_2O和50%Mn(NO_3)_2水溶液为铜源和锰源,K_2CO_3为沉淀剂,采用沉淀法和共沉淀法制备单一Cu、Mn氧化物催化剂和Cu-Mn-O复合氧化物催化剂,用于催化N_2O直接分解反应,并利用N_2物理吸附-脱附、XRD、FT-IR和TPR等进行表征。结果表明,单一Cu和Mn氧化物分别以体相CuO和Mn2O_3物相形式存在,Cu-Mn-O复合氧化物中除形成CuMn_2O_4尖晶石物相外,还有一定量小晶粒CuO,较单一氧化物具有更加优异的还原性能,表现出较高的催化N_2O直接分解活性。在空速10 000 h^(-1)和N_2O体积分数0.1%条件下,Cu-Mn-O复合氧化物催化剂可在440℃催化N_2O完全分解,分别较单一Cu和Mn氧化物催化剂降低了40℃和60℃。

Using aqueous solution of Cu（NO3）2·3H2O and 50% Mn（ NO3）2as raw material,and K2CO3 as the precipitator,respectively,the single Cu oxide,Mn oxide and Cu-Mn-O composite oxide catalysts were prepared by the precipitation and co-precipitation methods. The catalytic performance of as-prepared catalysts for the catalytic decomposition of N2 O was investigated. The structure and properties of the catalysts were characterized by N2-physisorption,XRD,FT-IR and TPR. The results showed that there existed Cu O phase and Mn2O3 phase respectively in the single Cu and Mn oxides. There was a certain amount of small crystalline grain Cu O besides the new formed spinel phase CuMn2O4 in Cu-Mn-O composite oxide,which possessed better reducibility than the single oxides. Under the reaction condition of N2O content0. 1% and GHSV 10 000 h-1,Cu-Mn-O composite oxide exhibited better catalytic activity for the direct decomposition of N2O,and the conversion of 100% could be obtained at 440 ℃,which was lower 40 ℃and 60 ℃ than that over the single Cu oxide and Mn oxide,respectively.