Dual-Copper Catalytic Site Formed in CuMFI Zeolite Makes Effective Activationof Ethane Possible Even at Room Temperature.
Dual-Copper Catalytic Site Formed in CuMFI Zeolite Makes Effective Activationof Ethane Possible Even at Room Temperature.
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CuMFI 沸石中形成的双铜催化位点使乙烷即使在室温下也能有效活化。
DOI：
10.1021/jp3022858
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
et al.
中科院分区：
文献类型：
--
作者：
Itadani;A. ; Torigoe;H.;;et al.
双阳离子位点在沸石中的作用已经在化学和工业中得到复兴，其针对各种气体的固定和活化;可以预期这样的位点比单阳离子位点更有效。我们的目的是澄清真实的活性中心的铜离子交换的MFI型沸石（CuMFI）乙烷（C2 H6）。当C_2H_6吸附在CuMFI中形成的Cu ~+上时，在2644和2582 cm ~（-1）处出现特征红外吸收带。扩展X射线吸收精细结构（EXAFS）数据表明，存在由两个Cu+离子桥C2 H6的双物种。密度泛函理论计算给出了明确的证据表明，这两个IR带是明显的，由于C2 H6吸附在双Cu+网站，而不是在一个单一的网站，这同意EXAFS数据。这些数据使我们得出结论，在CuMFI样品中的双Cu+网站是必不可少的有效激活C2 H6通过C2 H6与两个Cu+离子的同时相互作用。
The role of dual-cation sites in zeolites has received a renaissance in chemistry and industry directed toward fixation and activation of various gases; such sites may be expected to be more efficient than a single-cation site. We aimed to clarify the real active centers in the copper-ion-exchanged MFI-type zeolite (CuMFI) for ethane (C2H6). A peculiar feature was found in the appearance of the characteristic IR bands at 2644 and 2582 cm–1when C2H6was adsorbed on Cu+formed in CuMFI. The existence of dual species composed of two Cu+ions bridging C2H6was clearly indicated by extended X-ray absorption fine structure (EXAFS) data. Density functional theory calculations gave clear evidence that the two IR bands are distinctly due to C2H6adsorbed on the dual-Cu+site and not on a single site; this agrees with the EXAFS data. These data lead us to conclude that the dual-Cu+site in the CuMFI sample is indispensable for efficient activation of C2H6through the simultaneous interaction of C2H6with two Cu+ions.