锰氧化物在载体上存在状态的研究

Study on forms of manganese oxides on supports

采用XPD、XPS、TEM等方法研究了由不同原料制备的MnO_x在载体上存在的状态。结果表明,MnO_x可在载体上单层分散,其最大单层分散量(或称阈值)分别为0.09gMn_2O_3/100m^2γ-Al_2O_3、0.03gMnO_2/100m^2γAl_2O_3、0.05gMn_2O_3/100m^2SiO_2、0.03gMnO_2/100m^2SiO_2;当MnO_x量超过阈值时出现MnO_x晶相,以Mn(NO_3)_2为原料在450℃焙烧制得的MnO_x晶相为β-MnO_2,以Mn(Ac)_2·4H_2O为原料在380℃焙烧得到的为γ-Mn_2O_3。

The forms of MnO_x prepared with different precursors on the supports were investigated by XRD, XPS, TEM etc. The results show that MnOx can disperse onto the supports to form a monolayer with a maximum dispersion capacity of 0. 09g Mn_2O_3,/l00m^2 γ-Al_2O_3 0. 03g MnO_2/ 100m^2 γ-Al_2O_3,0.05gMn_2O_3/100m^2 SiO_2 and 0. 03g MnO_2/100m^2 SiO_2 respectively. As long as the amount of MnOx exceeds the monolayer capacity, there are residual crystallines of MnOx. When using Mn (NO_3)_2 as the precursor, β-MnO_2 is formed at a calcination temperature of 450℃ and when using Mn(Ac)_2. H_2O, γ-Mn_2O_3 is formed at 380℃.