SO(2-)4/Ti-Al-O固体超强酸的酸强度及催化性能

ＳＯ４＾２＾－／Ｔｉ－Ａｌ－Ｏ型固体超强度酸可用于邻苯二甲酸二辛酯（ＤＯＰ）的合成，当Ｔｉ／Ａｌ原子比为２时，催化性能优于ＳＯ４＾２＾－／ＴｉＯ２，且催化剂的制备条件对其酸强度，表面积和催化活性有较大的影响。使用ＴＰＤ技术对催化剂的酸强度分布进行了表征，发现在ＳＯ４＾２＾－／Ｔｉ－Ａｌ－Ｏ型固体超强度酸中，存在着三种酸中心（弱酸，中等强度酸和超强酸），中等强度的酸中心浓度与ＤＯＰ合成的催化活性有有

STUDY ON ACID STRENGTH AND CATALYTIC ACTIVITIES OF SO_4~(2-)/Ti-Al-O SOLID SUPERACIDS

SO4~(2-) /Ti-Al-O solid superacids were used for the esterification of phthalic anhydride with 2-ethyl-hexyl alcohol. As the atom ratio of Ti/ Al was 2, its catalytic activity was better than that of SO4~(2-)/TiO2. The acid strength, surface area and catalytic activity of the catalyst were affected by its preparation conditions obviously. The TPD of a catalyst adsorbed pyridine was used to characterize the acid strength distribution of the catalysts. It was found that there were three kinds of the acid site (weak acid, middle acid and superacid) on the SO4~(2-)/Ti-Al-O solid superacids. And the concentration of the middle-acid site on the catalysts was directly proportional to their catalytic activity for the esterification. For the Ti-substrate solid superacids, the presence of SO4~(2-) could inhibit the growth of crystalline phase of TiO2 in catalysts. Adding Al into TiO2 and SO4~(2-)/TiO2, the surface area could be increased greatly.