Bertheussen Erlend, Verdaguer-Casadevall Arnau, Ravasio Davide, Montoya Joseph H, Trimarco Daniel B, Roy Claudie, Meier Sebastian, Wendland Jürgen, Nørskov Jens K, Stephens Ifan E L, Chorkendorff Ib
Department of Physics, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark.
Carlsberg Laboratory, Gamle Carlsberg vej 4, 1799, København V, Denmark.
Angew Chem Int Ed Engl. 2016 Jan 22;55(4):1450-4. doi: 10.1002/anie.201508851. Epub 2015 Dec 21.
Oxide-derived copper (OD-Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50% Faradaic efficiency at -0.3 V (vs. RHE). By using static headspace-gas chromatography for liquid phase analysis, we identify acetaldehyde as a minor product and key intermediate in the electroreduction of CO to ethanol on OD-Cu electrodes. Acetaldehyde is produced with a Faradaic efficiency of ≈5% at -0.33 V (vs. RHE). We show that acetaldehyde forms at low steady-state concentrations, and that free acetaldehyde is difficult to detect in alkaline solutions using NMR spectroscopy, requiring alternative methods for detection and quantification. Our results represent an important step towards understanding the CO reduction mechanism on OD-Cu electrodes.
氧化物衍生铜（OD-Cu）电极在液体燃料的CO还原反应中展现出前所未有的性能，在-0.3 V（相对于可逆氢电极，RHE）时，生成乙醇和乙酸盐的法拉第效率大于50%。通过使用静态顶空气相色谱法进行液相分析，我们确定乙醛是OD-Cu电极上CO电还原为乙醇过程中的次要产物和关键中间体。在-0.33 V（相对于RHE）时，乙醛的法拉第效率约为5%。我们发现，乙醛以低稳态浓度生成，并且在碱性溶液中使用核磁共振光谱法很难检测到游离乙醛，因此需要采用其他检测和定量方法。我们的结果是朝着理解OD-Cu电极上CO还原机理迈出的重要一步。
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