The importance of surface morphology in controlling the selectivity of polycrystalline copper for CO2 electroreduction

Center for Individual Nanoparticle Functionality, Department of Physics, Building 312, Technical University of Denmark, DK-2800 Lyngby, Denmark.
Physical Chemistry Chemical Physics (Impact Factor: 4.49). 11/2011; 14(1):76-81. DOI: 10.1039/c1cp22700a
Source: PubMed


This communication examines the effect of the surface morphology of polycrystalline copper on electroreduction of CO(2). We find that a copper nanoparticle covered electrode shows better selectivity towards hydrocarbons compared with the two other studied surfaces, an electropolished copper electrode and an argon sputtered copper electrode. Density functional theory calculations provide insight into the surface morphology effect.

Download full-text


Available from: Ana Sofia Varela Gasque, Oct 19, 2015
  • Source
    • "Several studies have shown that the selectivity of Cu catalyst towards CO 2 reduction was dependent highly on its surface structure , more specifically the crystal facets [14] [15] [16] [17]. This finding has inspired intensive interests in surface modification techniques, such as electrochemical deposition [18] [19], alloying [20], ligandstabilization [21] and other approaches [22] [23] [24]. Although the product selectivity was altered in these approaches, they also led to an increased hydrogen production. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The existing Cu-based electrocatalysts for electrochemical reduction of CO 2 to chemical commodities suffer instability and large reaction overpotentials. Here we report a novel Cu nanoflower (NF) catalyst with a unique 3D chrysanthemum-like structure. Derived from CuO NFs, the Cu NFs were found to effi-ciently catalyze the CO 2 reduction with 400 mV lower overpotential than polycrystalline Cu. Besides, H 2 production was suppressed to be below 25% in terms of Faradaic efficiency in a wide potential win-dow, implying an excellent catalytic selectivity. Prolonged electrolysis showed that the Cu NFs kept a high catalytic activity towards CO 2 reduction for over 9 h. In addition, for the first time, the deposition of amorphous carbon on the electrodes after catalysis was directly observed in this study. The reaction pathways of electrocatalytic CO 2 reduction and the involvement of the surface carbon in this process were elucidated.
    Electrochimica Acta 07/2014; 139:137-144. DOI:10.1016/j.electacta.2014.06.034 · 4.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The latest advances in solar-fuel generation were the focus of the 'Advanced Materials for Solar-Fuel Generation' symposium at the 2011 MRS Fall meeting in Boston. Materials scientists discuss the most viable approaches to produce high-energy-density fuels from sunlight that can be implemented in existing infrastructures. In the first approach, solar energy is harvested as electricity and when present in surplus amounts used to hydrogenate CO 2 in an electrolyser-type unit. The aim is to produce fuels with higher energy density. Nørskov provided theoretical insights on the reaction mechanism of CO 2 reduction and explained why Cu is so far the best suited catalyst for the reaction high selectivity towards hydrocarbons. In the second approach, the electrical wires are entirely eliminated from the device and, as proposed by Heinz Frei, fuels are produced directly from solar light through the formation of electron-hole pairs in a semiconductor catalyst.
    Nature Material 02/2012; 11(2):100-1. DOI:10.1038/nmat3233 · 36.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Modified Cu electrodes were prepared by annealing Cu foil in air and electrochemically reducing the resulting Cu(2)O layers. The CO(2) reduction activities of these electrodes exhibited a strong dependence on the initial thickness of the Cu(2)O layer. Thin Cu(2)O layers formed by annealing at 130 °C resulted in electrodes whose activities were indistinguishable from those of polycrystalline Cu. In contrast, Cu(2)O layers formed at 500 °C that were ≥~3 μm thick resulted in electrodes that exhibited large roughness factors and required 0.5 V less overpotential than polycrystalline Cu to reduce CO(2) at a higher rate than H(2)O. The combination of these features resulted in CO(2) reduction geometric current densities >1 mA/cm(2) at overpotentials <0.4 V, a higher level of activity than all previously reported metal electrodes evaluated under comparable conditions. Moreover, the activity of the modified electrodes was stable over the course of several hours, whereas a polycrystalline Cu electrode exhibited deactivation within 1 h under identical conditions. The electrodes described here may be particularly useful for elucidating the structural properties of Cu that determine the distribution between CO(2) and H(2)O reduction and provide a promising lead for the development of practical catalysts for electrolytic fuel synthesis.
    Journal of the American Chemical Society 04/2012; 134(17):7231-4. DOI:10.1021/ja3010978 · 12.11 Impact Factor
Show more