Cyclohexane oxidation continues to be a challenge
Cyclohexane oxidation continues to be a challenge
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DOI：
10.1016/s0926-860x(01)00472-0
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发表时间：
2001-03
影响因子：
5.5
通讯作者：
U. Schuchardt;D. Cardoso;Ricardo Sercheli;Ricardo Pereira;R. S. D. Cruz;M. C. Guerreiro;D. Mandelli-
中科院分区：
文献类型：
--
作者：
U. Schuchardt;D. Cardoso;Ricardo Sercheli;Ricardo Pereira;R. S. D. Cruz;M. C. Guerreiro;D. Mandelli-
为了开发在温和条件下氧化环己烷的新催化剂，人们进行了许多努力。在此，我们回顾了最有趣的系统，这一过程与不同的氧化剂，如过氧化氢，叔丁基过氧化氢和分子氧。使用H2 O2，Na-GeX已被证明是最稳定和活性的催化剂。中孔TS-1和Ti-MCM-41也是稳定的，但使用其他金属如Cr、V、Fe和Mo会导致金属的浸出。基于双核锰（IV）配合物的均相体系也被证明是令人感兴趣的。当使用t-BuOOH时，活性体系是基于Ru、Co和Cu的酞菁以及双核钌和钯的多氧六环酸盐。含有不同过渡金属的微孔金属硅酸盐在反应过程中表现出金属的浸出。与过氧化氢和叔丁基过氧化氢相比，分子氧可直接用作氧化剂，并减少活性物质的浸出。金属铝磷酸盐（金属：Mn、Fe、Co、Cu、Cr V）在这样的条件下是活性的并且相对稳定。Mn-AlPO-36直接产生己二酸，但应避免大量的羧酸，因为它们会导致金属从催化剂中浸出。稀土离子交换Y型分子筛也表现出良好的选择性和活性。在综述的最后一部分，对环己醇和环己酮的生产以及己二酸的直接合成的新的替代策略进行了讨论。
Many efforts have been made to develop new catalysts to oxidize cyclohexane under mild conditions. Herein, we review the most interesting systems for this process with different oxidants such as hydrogen peroxide, tert-butyl hydroperoxide and molecular oxygen. Using H2O2, Na-GeX has been shown to be a most stable and active catalyst. Mesoporous TS-1 and Ti-MCM-41 are also stable, but the use of other metals such as Cr, V, Fe and Mo leads to leaching of the metal. Homogeneous systems based on binuclear manganese(IV) complexes have also been shown to be interesting. When t-BuOOH is used, the active systems are those phthalocyanines based on Ru, Co and Cu and polyoxometalates of dinuclear ruthenium and palladium. Microporous metallosilicates containing different transition metals showed leaching of the metal during the reactions. Molecular oxygen can be used directly as an oxidant and decreases the leaching of active species in comparison to hydrogen peroxide and tert-butyl hydroperoxide. Metal aluminophosphates (metal: Mn, Fe, Co, Cu, Cr V) are active and relatively stable under such conditions. Mn-AlPO-36 yields directly adipic acid, but large amounts of carboxylic acids should be avoided, as they cause metal leaching from the catalysts. Rare earth exchanged zeolite Y also shows good selectivity and activity. In the last part of the review, novel alternative strategies for the production of cyclohexanol and cyclohexanone and the direct synthesis of adipic acid are discussed.