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生物柴油是一种绿色的可再生能源,主要通过酯交换反应生产。催化剂在酯交换反应中起重要作用,固体酸催化剂因污染少、效率高、易分离而成为研究热点。本文介绍了固体酸催化制备生物柴油的反应机理,综述了国内外近几年生物柴油制备中所用固体酸催化剂的研究进展,分为固体杂多酸、无机酸盐、金属氧化物及其复合物、沸石分子筛及阳离子交换树脂等,分析了催化剂的制备流程、反应操作条件和反应结果等,得出固体酸在催化含有大量水分和游离酸的油脂酯交换反应方面具有独特的优势,且符合生物柴油绿色生产的要求,是需要进一步研究和开发的方向。 相似文献
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固体酸催化剂的分子设计初探 总被引:11,自引:0,他引:11
高效固体酸催化剂无论对现有工业生产还是从环保考虑都是十分需要的。鉴于均相和多相酸催化剂的活性部位有诸多共同特点(化学性质和对反应机理以及控制步骤速度的影响),根据现代均相酸催化理论,以Bronsted酸和Lewis酸为例,广泛讨论了类似活性部位的异同,探讨了活性部位在均相和多相酸催化反应中结构和机理上的类似性以及固体晶格在形成固体酸催化剂活性部位时的特殊作用,并对阳碳机理作了评价,最后对固体酸催化剂的设计提出了建议。 相似文献
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Products formed by rearrangement of epoxide compounds provide useful intermediates in organic syntheses and some of them are valuable as raw materials in the chemical industry. Many studies on the catalytic rearrangement of the epoxides have been made. The reactions which have been used most frequently are homogeneous with acid or base catalysts such as BF3, MgBr2, t-BuOK, or lithium dialkylamides; the acid catalysts form mainly carbonyl compounds (ketone and aldehyde) and the base catalysts in most cases yield allylic alcohols. Recently the heterogeneous reaction over solid catalysts was also investigated, but the catalysts used were just alumina and silica gel, solid acid and base catalysts, and it is very recent that various kinds of the solid acids and bases have been used as catalysts for epoxide isomerization, especially by the authors (Section VI-A). Studies with molten salts are few, and investigations with metal complex and organometal catalysts have just begun. 相似文献
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Products formed by rearrangement of epoxide compounds provide useful intermediates in organic syntheses and some of them are valuable as raw materials in the chemical industry. Many studies on the catalytic rearrangement of the epoxides have been made. The reactions which have been used most frequently are homogeneous with acid or base catalysts such as BF3, MgBr2, t-BuOK, or lithium dialkylamides; the acid catalysts form mainly carbonyl compounds (ketone and aldehyde) and the base catalysts in most cases yield allylic alcohols. Recently the heterogeneous reaction over solid catalysts was also investigated, but the catalysts used were just alumina and silica gel, solid acid and base catalysts, and it is very recent that various kinds of the solid acids and bases have been used as catalysts for epoxide isomerization, especially by the authors (Section VI-A). Studies with molten salts are few, and investigations with metal complex and organometal catalysts have just begun. 相似文献
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文章详细介绍了目前国内不同的催化剂合成氯乙酸酯。这些催化剂主要包括:磺酸类、固载杂多酸、固体超强酸、无机盐、负载型催化剂,这些催化剂在化学反应中的使用改善了反应条件,提高了产品的收率,各有自己的优缺点。 相似文献
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固体酸催化剂因其具有对多种化学反应有较高活性与选择性、回收重复利用效率较高等优点,已作为绿色环境友好型催化材料备受人们关注。本文主要综述了近年来国内外对各类型固体超强酸、杂多酸固体酸、离子交换树脂的研究近况,并提出了对今后固体酸发展的展望。 相似文献
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丙烯二聚反应是生产4-甲基-1-戊烯、1-己烯等端碳烯烃的重要手段,其产物可作为特种高分子材料单体、汽油添加剂和化工有机中间体,关键技术在于高效催化剂的开发。非均相催化剂相比于均相催化剂因易回收、对环境污染小等优点受到了学者们的广泛关注。本文综述了丙烯二聚非均相催化剂的研究进展,依据固体碱催化剂与固体酸催化剂在丙烯二聚反应中不同的反应机理,比较了两者各自的优缺点。回顾了固体碱催化剂的发展历程及工业化应用,并以碱金属钾为例总结了反应机理。详细介绍了固体酸催化剂中的固体磷酸催化剂、分子筛催化剂和负载型过渡金属催化剂。针对固体碱催化剂制备条件苛刻等问题,提出了改善催化装置的新思路;针对固体酸催化剂选择性不足的劣势,指出了应该进一步完善机理,并合理设计酸性载体与过渡金属相结合的催化剂。 相似文献