Selective carbonylation of dimethyl ether to methyl acetate catalyzed by acidic zeolites
Selective carbonylation of dimethyl ether to methyl acetate catalyzed by acidic zeolites
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DOI：
10.1002/anie.200503898
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发表时间：
2006-01-01
影响因子：
16.6
通讯作者：
Iglesia, E
中科院分区：
文献类型：
--
作者：
Cheung, P;Bhan, A;Iglesia, E
甲醇羰基化生产乙酸目前使用铑和铱金属有机配合物和碘化物助催化剂。[1-3]沸石[4-9]和Keggin多金属氧酸盐簇[10-13]也催化醇和醚的羰基化（Koch反应）以形成羧酸和酯。通过醇离解、烯烃质子化或烷烃在酸性位点去质子化形成的表面烷基与CO反应形成酰基离子，然后形成羧酸和酯，如异丁烷在硫酸化氧化锆上的反应[14]和叔丁醇在酸性ZSM 5、莫尔、ZSM-5和Y-沸石上的反应[5，7，8]形成特戊酸。甲醇和二甲醚（DME）在酸性沸石和多金属氧酸盐簇上的羰基化同时发生副反应（方案1）和显著的催化剂失活。[4，6，9-13]我们在此报道了用于在低温（423- 463 K）下DME羰基化为乙酸甲酯的基于沸石的稳定且高选择性（> 99%）的无卤化物催化剂。反应速率比甲醇羰基化高得多，因为水可以在CO结合位点竞争性吸附和/或引起平行的甲醇脱水
Methanol carbonylation is currently used to produce acetic acid with Rh and Ir organometallic complexes and iodide cocatalysts.[1–3] Zeolites [4–9] and Keggin polyoxometallate clusters [10–13] also catalyze the carbonylation of alcohols and ethers (Koch reaction) to form carboxylic acids and esters. Surface alkyl groups, formed by alcohol dissociation, alkene protonation, or alkane deprotonation at acidic sites react with CO to form acylium ions, which then form carboxylic acids and esters, as in the reactions of isobutane on sulfated zirconia [14] and tert-butyl alcohol [5, 7, 8] on acidic ZSM5, MOR, BEA, and Y-zeolites to form pivalic acid. Carbonylation of methanol and dimethyl ether (DME) on acidic zeolites and polyoxometallate clusters occurs concurrently with side reactions (Scheme 1) and significant catalyst deactivation.[4, 6, 9–13]We report herein stable and highly selective (> 99%) halide-free catalysts based on zeolites for DME carbonylation to methyl acetate at low temperatures (423–463K). The reaction rates are much higher than for methanol carbonylation because water may adsorb competitively at CO binding sites and/or cause parallel methanol dehydration