Further Evidence for the Existence of a Dual-Cu^+ Site in MFI Working as the Efficient Site for C_2H_6 Adsorption at Room Temperature
Further Evidence for the Existence of a Dual-Cu^+ Site in MFI Working as the Efficient Site for C_2H_6 Adsorption at Room Temperature
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进一步证明 MFI 中存在双 Cu^ 位点，作为室温下 C_2H_6 吸附的有效位点
DOI：
10.1021/la4018568
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发表时间：
2013
期刊：
影响因子：
3.9
通讯作者：
and Y. Kuroda
中科院分区：
文献类型：
--
作者：
A. Itadani;Y. Sogawa;A. Oda;H. Torigoe;T. Ohkubo;and Y. Kuroda
我们最近澄清了以下一点：由铜离子交换的MFI型沸石（CuMFI）中形成的一对一价铜离子（Cu+）组成的双型位点，即使在室温下也可作为强乙烷（C2 H6）吸附的活性中心，而不是由Cu+离子组成的单型位点。然而，在CuMFI的双Cu+网站的字符尚未完全理解。在这项研究中，我们已经阐明的性质的活性位点C2 H6的红外（IR）和量热数据的基础上。根据所得结果，我们得出的结论是，双Cu+网站组成的Cu+离子给出的吸附能为100 kJ mol-1和2151 cm-1的吸收带的一氧化碳（用作探针分子）在室温下作为吸附位C2 H6。我们还评估，第一次，双Cu+网站和C2 H6大力之间的相互作用，通过直接测量吸附热。我们记录的67 kJ mol-1的值高于该样品中单个Cu+位点的值，也高于其他样品，如NaMFI和HMFI。
We have recently clarified the following point: a dual-type site, which is composed of a pair of monovalent copper ions (Cu+) formed in a copper-ion-exchanged MFI-type zeolite (CuMFI), functions as the active center for strong ethane (C2H6) adsorption even at room temperature rather than a single-type site composed of a Cu+ion. However, the character of the dual-Cu+site in a CuMFI is not yet fully understood. In this study, we have elucidated the nature of the active sites for C2H6based on infrared (IR) and calorimetric data. On the basis of the results obtained, we came to the conclusion that the dual-Cu+site composed of Cu+ions giving the adsorption energy of 100 kJ mol–1and the absorption band at 2151 cm–1for carbon monoxide (used as a probe molecule) at room temperature functions as an adsorption site for C2H6. We also evaluated, for the first time, the interaction between the dual-Cu+site and C2H6energetically, by the direct measurement of heat of adsorption. The value of 67 kJ mol–1that we recorded was higher than that for the single-Cu+site in this sample and also for other samples, such as NaMFI and HMFI.