Spectroscopic Observation of a Hydrogenated CODimer Intermediate During CO Reduction on Cu(100) Electrodes
Spectroscopic Observation of a Hydrogenated CODimer Intermediate During CO Reduction on Cu(100) Electrodes
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DOI：
10.1002/anie.201700580
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发表时间：
2017-03-20
影响因子：
16.6
通讯作者：
Koper, Marc T. M.
中科院分区：
文献类型：
--
作者：
Perez-Gallent, Elena;Figueiredo, Marta C.;Koper, Marc T. M.
二氧化碳和一氧化碳可以在铜电催化剂上电化学还原为有用的产物，如乙烯和乙醇。该工艺尚待优化，确切的机理和相应的反应中间体仍在争论中或未知。特别地，已经假设C-C键的形成通过CO二聚化和进一步氢化进行。虽然这一假设的计算支持存在，直接的实验证据一直难以捉摸。在这项工作中，我们检测氢化二聚体中间体（OCCOH）使用傅里叶变换红外光谱在低过电位在LiOH溶液。密度泛函理论计算支持我们所观察到的振动带的分配。该中间体的形成是结构敏感的，因为它仅在Cu（100）上而不是Cu（111）上的CO还原期间观察到，与先前的实验和计算观察一致。
Carbon dioxide and carbon monoxide can be electrochemically reduced to useful products such as ethylene and ethanol on copper electrocatalysts. The process is yet to be optimized and the exact mechanism and the corresponding reaction intermediates are under debate or unknown. In particular, it has been hypothesized that the C-C bond formation proceeds via CO dimerization and further hydrogenation. Although computational support for this hypothesis exists, direct experimental evidence has been elusive. In this work, we detect a hydrogenated dimer intermediate (OCCOH) using Fourier transform infrared spectroscopy at low over-potentials in LiOH solutions. Density functional theory calculations support our assignment of the observed vibrational bands. The formation of this intermediate is structure sensitive, as it is observed only during CO reduction on Cu(100) and not on Cu(111), in agreement with previous experimental and computational observations.