Fig. 4: Electrochemical properties and mechanism of NO3−RR ammonia synthesis.
From: Fe/Cu diatomic catalysts for electrochemical nitrate reduction to ammonia
a LSV curves of Fe/Cu-HNG, Fe-HNG, Cu-HNG, and HNG in an electrolyte of 1 M KOH and 0.1 M KNO3. b NH3 FEs of Fe/Cu-HNG at varied potentials. c NH3 yield rates of Fe/Cu-HNG, Fe-HNG, and Cu-HNG. d 1H NMR spectra of the electrolytes after electrocatalysis at −0.3 V (vs RHE) using 0.1 M 15NH4+ or 0.01 M 14NH4+ in 1 M KOH as nitrogen source (1H NMR of the fresh electrolytes marked as 15NO3− and 14NO3− were provided as the controls). e Chronoamperometric curve of Fe/Cu-HNG at −0.3 V vs RHE for 24 h. f Cycling tests of Fe/Cu-HNG for the NO3−RR. g Comparison of the cathodic NH3 EEs obtained using the Fe/Cu-HNG, Fe-HNG, and Cu-HNG catalysts. h Time-dependent concentration changes of NO3− and ammonia during the NO3−RR using Fe/Cu-HNG. i DEMS analyses of nitrogen species during the NO3−RR (each cycle is one LSV scan from 0.1 to −0.6 V vs RHE).
