FTIR study of the interaction of CO with pure and silica-supported copper(I) oxide
FTIR study of the interaction of CO with pure and silica-supported copper(I) oxide
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DOI：
10.1016/s0039-6028(98)00331-8
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发表时间：
1998-08-25
期刊：
影响因子：
1.9
通讯作者：
Arean, CO
中科院分区：
文献类型：
--
作者：
Scarano, D;Bordiga, S;Arean, CO
为了研究CO在Cu2O和二氧化硅负载的Cu2O微晶上吸附的红外光谱与颗粒形貌之间的关系（通过SEM和TEM分析得到），对CO在Cu2O和二氧化硅负载的Cu2O微晶上的吸附进行了比较FTIR光谱研究。晶体形态的建模也通过原子模拟的方式进行。并与电镜图进行了比较。在两个样品上，CO吸附发生在Cu(I)离子上，Cu(I)离子位于优势面和非极性面（111）。在吸附CO的红外光谱中，在2158和2162 cm（-1）和2127和2132 cm(-1)（强而不可逆）处同时存在两种组分，它们分别向下移动约δ一致性到- 8-10 cm（-1）和δ一致性到- 12-13 cm(-1)，这是二维相内横向相互作用逐步建立的结果，用两种可选择的模型来解释。第一个模型解释了在Cu2O（111）表面的两个不同的Cu(I)位点（单配位和双配位）上CO吸附的两个IR波段的存在。第二个模型则相反，观察到的IR偶联与Cu(I)(CO)(2)在单配位Cu(I)位点上的形成有关。根据松弛和未松弛（111）面的两个表面位置的电场计算，第二种模型似乎更合适。(C) 1998 Elsevier Science B.V.版权所有
A comparative FTIR spectroscopic study of CO adsorption on Cu2O and on silica-supported Cu2O microcrystals has been carried out in order to investigate the relations between the IR spectrum of adsorbed CO and the morphology of the particles las obtained by SEM and TEM analyses). Modelling of the crystal morphology was also performed by means of atomistic simulations. and the results were compared with the electron micrographs. On both samples, CO adsorption occurs on Cu(I) ions located on the predominant and unpolar (111) faces. The simultaneous presence in the IR spectra of adsorbed CO of two components at 2158 and 2162 cm(-1) tweak and fully reversible) and at 2127 and 2132 cm(-1) (strong and quite irreversible), which shift downward of about Deltacongruent to - 8-10 cm(-1) and Deltacongruent to - 12-13 cm(-1), respectively, as a consequence of the progressive building up of lateral interactions within the bidimensional phase, is explained in terms of two alternative models. The first model explains the presence of the two IR bands in terms of CO adsorption on the two different Cu(I) sites (mono and bicoordinated) present on the (111) face of Cu2O Following the second model, the observed IR doublet is on the contrary associated with the formation of Cu(I)(CO)(2) species on monocoordinated Cu(I) sites. On the basis of the calculated electric field at the two surface sites of the relaxed and unrelaxed (111) Faces, the second model seems to be more appropriate. (C) 1998 Elsevier Science B.V. All rights reserved.