摘要
根据将磁性材料和固体酸进行组装的设想 ,成功制备了磁性纳米固体酸催化剂 .纳米级磁性前体———磁基体(Fe3 O4 )的磁性、粒子尺寸受到Fe2 + /Fe3 + 投料比和用于沉淀的NaOH浓度的显著影响 ;不同复合方法也对磁性固体酸催化剂ZrO2 /Fe3 O4 的酯化催化性能影响显著 .XRD ,XPS ,TEM ,比表面积测定 ,元素组成分析及磁学性能测定等表征结果证实 ,新型催化剂以磁性材料为核 ,固体酸催化剂活性组分包覆在其外部形成包覆型的磁性纳米催化剂 .该系列催化剂均具有较小的粒子尺寸、较强的磁性及较高的酯化催化活性 ;并且易于通过磁场进行回收 ,使用寿命较长 .它们对乙酸与正丁醇酯化反应的催化活性随着ZrO2 含量增加而提高 .催化剂中ZrO2 的晶化温度因为Fe3 O4 的存在而升高 ,有利于催化剂活性的保持 .热处理温度会对催化剂的磁性及催化活性产生影响 .
Nano-size cores of Fe3O4 with the strongest magnetism were prepared with a proper feeding ratio of Fe2+/Fe3+ and a suitable concentration of NaOH solution. Then solid acid ZrO2 was deposited over the magnetic cores to form a novel magnetic nano-size solid acid catalyst: ZrO2/Fe3O4. The new catalysts were characterized by techniques such as XRD, XPS, TEM and by the measurements of specific surface area as well as magnetic properties, etc. They showed high catalytic activities for esterification of acetic acid with butyric mellow. The new catalysts can easily be separated from the reaction system by magnetism.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2002年第2期298-304,185,共7页
Acta Chimica Sinica
基金
国家自然科学基金 (No .2 0 0 76 0 0 3)
中石化总公司 (No .X5 0 0 0 0 8)资助项目
