DoubleBond Migration of an Olefin without Protonated Species on H(D) Form Zeolites
DoubleBond Migration of an Olefin without Protonated Species on H(D) Form Zeolites
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不含质子化物质的烯烃在 H(D) 型沸石上的双键迁移
DOI：
10.1021/jp971812t
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发表时间：
1997
影响因子：
3.3
通讯作者：
K. Domen
中科院分区：
文献类型：
--
作者：
J. Kondo;L. Shao;A. Wakabayashi;K. Domen
在低于 230 K 且没有质子化的情况下，发现了 1-丁烯在沸石、ZSM-5 和丝光沸石 (MOR) 的强布朗斯台德酸位点 (BAS) 上的双键迁移 (DBM) 的新反应路径，D-ZSM-5 上的活化能为 49 ± 4 kJ·mol-1，D-MOR 上的活化能为 38 ± 8 kJ·mol-1 （DM20）。通过使用氘化沸石，证明质子化中间体对于ZSM-5和MOR的BAS上1-丁烯转化为氢键顺式和反式2-丁烯不是必需的。如果假定是广泛接受的质子化中间体，则酸性 OD 基团应在 1-丁烯到 2-丁烯的 DBM 上转化为 OH 基团。然而，即使在双键迁移之后，与1-丁烯形成1:1络合物的沸石的OD基团仍然保持不变。 OD基团由于质子转移而发生的同位素交换反应发生在比DBM更高的温度下。然而，氘化八面沸石 (FAU) 沸石（DY5.6 和 DY4.8）上的 DBM 伴随着 H/D 交换 r...
A novel reaction path was found for the double-bond migration (DBM) of 1-butene on very strong Bronsted acid sites (BAS) of zeolites, ZSM-5 and mordenite (MOR), in the absence of protonation below 230 K with the activation energies of 49 ± 4 kJ·mol-1 on D-ZSM-5 and 38 ± 8 kJ·mol-1 on D-MOR (DM20). By using deuterated zeolites, it was proved that the protonated intermediate is not essential to the conversion of the 1-butene to the hydrogen-bonded cis- and trans-2-butenes on the BAS of ZSM-5 and MOR. If the widely accepted protonated intermediate is assumed, the acidic OD groups should be converted to OH groups upon the DBM of 1-butene to 2-butenes. Nevertheless, the OD groups of zeolites forming 1:1 complex with 1-butene remained unchanged even after the double-bond migration. The isotope exchange reaction of OD groups due to the proton transfer occurred at higher temperature than the DBM. However, the DBM on a deuterated faujasite (FAU) zeolite (DY5.6 and DY4.8) proceeded accompanied by the H/D exchange r...