CO <sub>2</sub> electrolysis to multicarbon products at activities greater than 1 A cm <sup>−2</sup>Graceful choreography for CO 2 and H 2 O One challenge for efficient electrochemical reduction of carbon dioxide (CO 2 ) is that the gas is hydrophobic, but many of its desirable reactions require water (H 2 O). García de Arquer et al. addressed this problem by combining a copper electrocatalyst with an ionomer assembly that intersperses sulfonate-lined paths for the H 2 O with fluorocarbon channels for the CO 2 . The electrode architecture enables production of two-carbon products such as ethylene and ethanol at current densities just over an ampere per square centimeter. Science , this issue p. 661
Enhanced Nitrate-to-Ammonia Activity on Copper–Nickel Alloys via Tuning of Intermediate AdsorptionYuhang Wang, Aoni Xu, Ziyun Wang et al.|Journal of the American Chemical Society|2020 Electrochemical conversion of nitrate (NO3–) into ammonia (NH3) recycles nitrogen and offers a route to the production of NH3, which is more valuable than dinitrogen gas. However, today’s development of NO3– electroreduction remains hindered by the lack of a mechanistic picture of how catalyst structure may be tuned to enhance catalytic activity. Here we demonstrate enhanced NO3– reduction reaction (NO3–RR) performance on Cu50Ni50 alloy catalysts, including a 0.12 V upshift in the half-wave potential and a 6-fold increase in activity compared to those obtained with pure Cu at 0 V vs reversible hydrogen electrode (RHE). Ni alloying enables tuning of the Cu d-band center and modulates the adsorption energies of intermediates such as *NO3–, *NO2, and *NH2. Using density functional theory calculations, we identify a NO3–RR-to-NH3 pathway and offer an adsorption energy–activity relationship for the CuNi alloy system. This correlation between catalyst electronic structure and NO3–RR activity offers a design platform for further development of NO3–RR catalysts.
CO <sub>2</sub> electrolysis to multicarbon products in strong acidPotassium helps CO 2 compete in acid Electrochemical reduction of carbon dioxide (CO 2 ) is a promising means of converting this greenhouse gas into valuable fuels and chemicals. However, two competing reactions restrict the efficiency of this process. In base, much of the CO 2 is trapped as carbonate before reduction; in acid, protons outpace CO 2 at catching electrons from the cathode. Huang et al. report that a high dose of potassium ions can help to solve the latter problem. By concentrating potassium ions at the electrode, high selectivity toward CO 2 reduction at high current in acid is possible, which the authors attribute to electrostatic stabilization of the desired adsorbates. Science , abg6582, this issue p. 1074
Molecular tuning of CO2-to-ethylene conversionMolecular enhancement of heterogeneous CO2 reduction