Electrochemical CO 2 reduction reaction can be used to produce value-added hydrocarbon fuels and chemicals by coupling with clean electrical energy. However, highly active, selective, and energy-efficient CO 2 conversion to multicarbon hydrocarbons, such as C 2 H 4 , remains challenging because of the lack of efficient catalysts. Herein, an ultrasonication-assisted electrodeposition strategy to synthesize CuO nanosheets for low-overpotential CO 2 electroreduction to C 2 H 4 is reported. A high C 2 H 4 Faradaic efficiency of 62.5% is achieved over the CuO nanosheets at a small potential of −0.52 V versus a reversible hydrogen electrode, corresponding to a record high half-cell cathodic energy efficiency of 41%. The selectivity toward C 2 H 4 is maintained for over 60 h of continuous operation. The CuO nanosheets are prone to in situ restructuring during CO 2 reduction, forming abundant grain boundaries (GBs). Stable Cu + /Cu 0 interfaces are derived from the low-coordinated Cu atoms in the reconstructed GB regions and act as highly active sites for CO 2 reduction at low overpotentials. In situ Raman spectroscopic analysis and density functional theory computation reveal that the Cu + /Cu 0 interfaces offer high *CO surface coverage and lower the activation energy barrier for *CO dimerization, which, in synergy, facilitates CO 2 reduction to C 2 H 4 at low overpotentials.
Here we report that in-situ reconstructed Cu two-dimensional (2D) defects in CuO nanowires during CO2RR lead to significantly enhanced activity and selectivity of C2H4 compared to the CuO nanoplatelets. Specifically,...
Electrocatalytic urea synthesis is a promising alternative
to the
energy-intensive conventional industrial process. However, it lacks
highly active and selective catalyst systems. Herein, we report a
Cu/ZnO stacked tandem gas-diffusion electrode (GDE) for selective
urea synthesis from electrocatalytic CO2 and nitrate reduction
reactions. The ZnO catalyst layer (CL) segment at the inlet provides
a high CO concentration to the downstream Cu CL segment, promoting
the conversion of NO3
– to *NH2. The CO-mediated NH2 formation accelerates the C–N
coupling rate for urea synthesis. As a result, the stacked GDE with
an optimal ZnO/Cu CL area ratio achieves a high Faradaic efficiency
of 37.4% and a high yield of 3.2 μmol h–1 cm–2 for urea at −0.3 V vs RHE under ambient conditions.
This work expands the application of tandem electrodes and realizes
the cascade C–N coupling reaction.
Although the electrocatalytic nitrate reduction reaction (NO3−RR) is an attractive NH3 synthesis route, it suffers from low yield due to the lack of efficient catalysts. Here, this work reports a novel grain boundary (GB)‐rich Sn‐Cu catalyst, derived from in situ electroreduction of Sn‐doped CuO nanoflower, for effectively electrochemical converting NO3− to NH3. The optimized Sn1%‐Cu electrode achieves a high NH3 yield rate of 1.98 mmol h−1 cm−2 with an industrial‐level current density of −425 mA cm−2 at −0.55 V versus a reversible hydrogen electrode (RHE) and a maximum Faradaic efficiency of 98.2% at −0.51 V versus RHE, outperforming the pure Cu electrode. In situ Raman and attenuated total reflection Fourier transform infrared spectroscopies reveal the reaction pathway of NO3−RR to NH3 by monitoring the adsorption property of reaction intermediates. Density functional theory calculations clarify that the high‐density GB active sites and the competitive hydrogen evolution reaction (HER) suppression induced by Sn doping synergistically promote highly active and selective NH3 synthesis from NO3−RR. This work paves an avenue for efficient NH3 synthesis over Cu catalyst by in situ reconstruction of GB sites with heteroatom doping.
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