Extended Data Fig. 2: Determination of possible product oxidation at the anode.
From: Coverage-driven selectivity switch from ethylene to acetate in high-rate CO2/CO electrolysis
1H-NMR spectra (a–c) and concentrations (d–f) of n-propanol (a, d), ethanol (b, e) and acetate (c, f) of the anolyte after electro-oxidation control experiments conducted under reaction conditions similar to that for CO2/CO electrolysis. The cathode and anode catalysts are Cu nanoparticle and Ir black, respectively. The anode electrolyte is 0.1 M KOH containing ethanol, n-propanol and acetate with concentrations similar to the actual values at 1 A cm−2 (11 mM ethanol, 7.5 mM n-propanol and 54 mM acetate), 2 A cm−2 (23.5 mM ethanol, 9.2 mM n-propanol and 115 mM acetate) and 3 A cm−2 (15 mM ethanol, 6 mM n-propanol and 186 mM acetate). The cathode is fed with Ar at a flow rate of 30 mL min−1. Only peaks assigned n-propanol, ethanol and acetate as well as DSS internal standard are observed from the 1H-NMR spectra, indicating the absence of any liquid products from the electro-oxidation of n-propanol, ethanol and acetate. Error bars represent the standard deviation from two independent measurements. The concentrations before and after electro-oxidation control measurements are the same at all applied current densities, also indicating that n-propanol, ethanol and acetate would not be electrochemically oxidized under reaction conditions.
