SO_4^（2－）－Fe_2O_3－Hβ－Al_2O_3催化剂制备方法对其表面性质和催化丙烯酸化反应性能的影响

EFFECT OF PREPARATION METHOD OF SO_4￣(2-)-Fe_2O_3-Hβ-Al_2O_3 CATALYSTS ON THEIR SURFACE PROPERTIES AND ETHERIFICATION OF PROPYLENE WITH ISOPROPANOL

首次以Ｈβ沸石为基础，采用一步浸渍法（Ａ）、机械研磨法（Ｂ）、沉积－沉淀法（Ｃ）及分步浸渍法（Ｄ）制备了ＳＯ－Ｆｅ２Ｏ３－Ｈβ－Ａｌ２Ｏ３催化剂，通过ＸＲＤ，ＸＰＳ，ＮＨ３－ＴＰＤ，ＦＴ－ＩＲ及化学吸附等手段对其物理化学性能进行了表征，并对其催化丙烯与异丙醇的酸化反应性能进行了评价．结果表明，在催化剂表面，ＳＯ，Ｆｅ２Ｏ３及Ｈβ沸石之间存在较强的化学作用，Ａ法和Ｃ法制备的催化剂具有明显的增强酸性；总酸量和Ｌ酸量增多，酸强度提高；该催化剂明显促进了丙烯醚化反应，其丙烯和异丙醇转化率分别由Ｈβ－Ａｌ２Ｏ３沸石的７．９８％和３５．１％提高到１４．８％和４０．０％，并发现该反应主要在Ｌ酸中心上进行．

he So-Fe2O3-Hβ-Al2O3 catalysts were prepared from Hβ zeolite. The process was realized for the first time by the use of one-step impregnation (A ), mix grind (B), deposition-precipitation (C) and multi-step impregnation (D).XRD, XPS,NH3-TPD, FT-IR and chemisorption were applied to characterize the catalyst.The behavior of propylene etherification with isopropanol in autoclave reactor was estimated.It revealed the stronger interaction among SO, Fe2O3 and Hβon catalyst surface. Method A and C strengthened the acidity evidently,and increased the total number of acid sites,acid strength and the number of L acid sites where the reaction mainly occurred. The catalyst obviously increased the conversion of propylene and isopropanol to 14.8%and 40.0% respectively as compared with 7. 92% and 35. 1% in the case of Hβ zeolite catalyst.