New insights into the electrochemical reduction of carbon dioxide on metallic copper surfaces
New insights into the electrochemical reduction of carbon dioxide on metallic copper surfaces
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DOI：
10.1039/c2ee21234j
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发表时间：
2012-05-01
影响因子：
32.5
通讯作者：
Jaramillo, Thomas F.
中科院分区：
文献类型：
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作者：
Kuhl, Kendra P.;Cave, Etosha R.;Jaramillo, Thomas F.
我们报告了对金属铜表面上的二氧化碳电化学还原的新见解，这是由于开发了一种具有前所未有的灵敏度的实验方法来识别和量化二氧化碳电还原产物。这涉及一种定制的电化学池，旨在最大限度地提高产品浓度，将其与气相色谱和核磁共振相结合，分别用于识别和定量气体和液体产品。我们研究了铜的各种潜力，观察到总共16种不同的二氧化碳还原产物，其中5种是首次报道，从而提供了迄今为止报道的最完整的反应化学图景。考虑到广泛生成的C-1-C-3产物的化学同一性及其周转频率的潜在依赖性，推导出了机理信息。我们讨论了一种包含类烯醇表面中间体的多碳产物的形成方案，作为一种可能的途径，解释了观察到的11种不同的C2+含氧产物的选择性，包括醛、酮、醇和羧酸。
We report new insights into the electrochemical reduction of CO2 on a metallic copper surface, enabled by the development of an experimental methodology with unprecedented sensitivity for the identification and quantification of CO2 electroreduction products. This involves a custom electrochemical cell designed to maximize product concentrations coupled to gas chromatography and nuclear magnetic resonance for the identification and quantification of gas and liquid products, respectively. We studied copper across a range of potentials and observed a total of 16 different CO2 reduction products, five of which are reported here for the first time, thus providing the most complete view of the reaction chemistry reported to date. Taking into account the chemical identities of the wide range of C-1-C-3 products generated and the potential-dependence of their turnover frequencies, mechanistic information is deduced. We discuss a scheme for the formation of multicarbon products involving enol-like surface intermediates as a possible pathway, accounting for the observed selectivity for eleven distinct C2+ oxygenated products including aldehydes, ketones, alcohols, and carboxylic acids.