Fig. 4.

Density functional theory calculations and stability. a Calculated absorption configurations (bottom) and corresponding Gibbs free energy diagrams of each step of NRR process on pristine Cu (black), Cu-0.04e⁻ (blue) and Cu-0.06e⁻(red) models. b The turnover frequency (TOF) values and NH₃ generation yield rates of Cu/PI-300 and benchmarked NRR electrocatalyst in the literature (details listed in Table S3). The i-t curves c of five runs of 6-h NRR reaction over a reused Cu/PI-300 at −0.4 V vs. RHE and corresponding NH₃ yield rates and TOF values d