镁铁和镁铁铝催化剂氢还原过程的研究

Study of Hydrogen Reduction of Mg-Fe and Mg-Fe-Al Oxide Catalysts

以水滑石为前体 ,制备了镁铁和镁铁铝复合氧化物催化剂 ,运用原位穆斯堡尔谱研究了催化剂在H2 气氛中的还原行为。结果表明 :由于Mg、Al的加入和固溶体的形成 ,相对地稳定了FeO物相 ,阻碍了H2 对铁离子的还原 ,使得Fe2 +进一步还原为金属Fe0 的能力减弱 ;在还原过程中催化剂首先生成含Fe2 +的固溶体FeO MgO或FeO MgO Al2O3,然后再完全还原成金属Fe0。

In situ Mssbauer spectroscopy was used to study reduction reaction of Mg Fe and Mg Fe Al mixed oxide catalysts with H2, which were derived from their hydrotalcite precursors. Effects of the metal component magnesium and aluminum on catalysts reduction property were also discussed. The results showed that the solid solution containing Fe2+was first produced during reduction process of the catalysts, then metal Fe0 accumulative precipitation when reduction temperature was elevated. And, for these oxide catalysts, the formed ferrous oxide was stabilized by the produced solid solution and the introduced metal magnesium with aluminum or magnesium without aluminum. Therefore, the ability that Fe2+in these samples could be reduced to metal iron was clearly decreased.