超临界浸渍干燥方法制备Fe_2O_3-SO_4^(2-)/Hβ-Al_2O_3催化剂

PREPARATION OF Fe_2O_3-SO_4^(2-)/Hβ-Al_2O_3 CATALYST BY SUPERCRITICAL IMPREGNATION-DRY METHOD

考察了HZSM 5、HY和Hβ沸石上气相合成甲基叔丁基醚 (MTBE)的反应性能 ,发现Hβ比其它沸石具有更高的催化活性。采用超临界浸渍 干燥方法将超强酸中心SO2 -4 Fe2 O3 引入Hβ上制成的Fe2 O3 SO2 -4/Hβ Al2 O3 催化剂 ,在实验条件下其催化合成MTBE的异丁烯转化率由常规浸渍 干燥方法制成的催化剂的 2 3 7%提高到 34 8% ,MTBE选择性为 10 0 %。应用NH3 TPD、吸附吡啶的红外光谱方法表征了该催化剂的表面酸性 ,其酸量和L酸 /B酸的比例较常规方法制成的催化剂分别提高了 2 2 %和 4 9%。XPS分析结果表明 ,该催化剂表面的Fe和S的化学环境发生了较大变化。BET比表面分析结果表明 。

The reaction performance on gas phase synthesis of MTBE was investigated over HZSM 5?HY and H β zeolites. It was found that H β showed higher activity than the other two zeolites. SO 2- 4 Fe 2O 3/H β Al 2O 3 catalyst was prepared by supercritical impregnation drying method. The iso butene conversion of this catalyst increased from 23.7% to 34.8% under experimental conditions, which was 11.1% higher than that of the catalyst prepared under conventional conditions, while the MTBE selectivity reached 100%. The surface acidity of catalysts was characterized by NH 3 TPD and Py IR. The acid amount and L/B acid ratio of supercritical phase catalyst were improved by 22% and 49%, respectively. Results of XPS indicated that chemical environment of Fe and S of supercritical phase catalysts greatly changed. Analytical result of BET surface area showed that surface areas of supercritical phase catalysts increased.