ABE Condensation over Monometallic Catalysts: Catalyst Characterization and Kinetics
ABE Condensation over Monometallic Catalysts: Catalyst Characterization and Kinetics
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DOI：
10.1002/cctc.201601507
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发表时间：
2017-02-01
期刊：
影响因子：
4.5
通讯作者：
Toste, F. Dean
中科院分区：
文献类型：
--
作者：
Goulas, Konstantinos A.;Gunbas, Gorkem;Toste, F. Dean
在此，我们介绍了催化剂的开发和丙酮-丁醇-乙醇（ABE）缩合动力学。在考察了文献报道的多种金属和碱性催化剂的组合后，发现烧成水滑石（HT）负载的Cu是ABE缩合的最佳催化剂。这种催化剂使反应速率比以前报道的催化剂提高了6倍。在CuHT和HT上对反应的动力学分析表明，反应速率的决定步骤是由醇在Cu表面形成的烷氧化物的C-H键活化。这一步之后是将生成的醛加入到丙酮烯酸酯中，丙酮烯酸酯是由在HT表面的基本位点上的丙酮去质子化形成的。醇的存在降低了醛醇的缩合速率，因为醇氧化物覆盖了催化位点。
Herein, we present work on the catalyst development and the kinetics of acetone-butanol-ethanol (ABE) condensation. After examining multiple combinations of metal and basic catalysts reported in the literature, Cu supported on calcined hydrotalcites (HT) was found to be the optimal catalyst for the ABE condensation. This catalyst gave a six-fold increase in reaction rates over previously reported catalysts. Kinetic analysis of the reaction over CuHT and HT revealed that the rate-determining step is the C-H bond activation of alkoxides that are formed from alcohols on the Cu surface. This step is followed by the addition of the resulting aldehydes to an acetone enolate formed by deprotonation of the acetone over basic sites on the HT surface. The presence of alcohols reduces aldol condensation rates, as a result of the coverage of catalytic sites by alkoxides.