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用硝酸铁或草酸铁铵作铁源浸渍介孔分子筛MCM - 41,并在高温下焙烧 ,均得到α -Fe2 O3 /MCM - 41分子筛体系。经XRD相定量外推法测定 ,不同铁源 ,α -Fe2 O3 在MCM - 41上的最大分散量不同。当以硝酸铁为铁源时 ,α -Fe2 O3 最大分散量为 0 .5 8gα -Fe2 O3 /gMCM - 41;当以草酸铁铵为铁源时 ,α -Fe2 O3 最大分散量为 0 .2 5 gα -Fe2 O3 /gMCM - 41,明显低于以硝酸铁为铁源时的最大分散量。这与草酸铁铵高温分解产生的氨对介孔分子筛MCM— 41孔结构有较强的破坏作用有关。
Mesoporous molecular sieve MCM - 41 was impregnated with iron nitrate or ammonium oxalate as iron source, and calcined at high temperature to obtain α - Fe2O3 / MCM - 41 molecular sieve system. According to the quantitative extrapolation of XRD phase, the maximum dispersion of α -Fe 2 O 3 in MCM-41 is different for different iron sources. When ferric nitrate was used as iron source, the maximum dispersion of α -Fe 2 O 3 was 0. 58gα -Fe 2 O 3 / gMCM-41. When iron oxalate was used as iron source, the maximum dispersion of α -Fe 2 O 3 was 0.2 5 gα -Fe 2 O 3 / gMCM - 41, which is obviously lower than the maximum dispersion when ferric nitrate is used as iron source. This is related to the strong destructive effect of ammonia produced by the pyrolysis of ammonium oxalate on the pore structure of the mesoporous molecular sieve MCM-41.