Fig. 6: Volcano relationships from EN computational studies.
From: Toward a mechanistic understanding of electrocatalytic nanocarbon
a EN cells which have been investigated in computational studies. b Thermodynamic plot which shows the free energy of each elemental step for ideal (blue) and non-ideal (red and gray) catalysts for the ORR at O and 1.23 V applied potential. c, d ORR volcano plots for single-SACs and bimetallic-SACs, showing the theoretical onset potentials (\({U}_{{\rm{RHE}}}^{{\rm{onset}}}\)) versus OH adsorption free energies (\({\triangle G}_{{\ast }_{{\rm{OH}}}}\)). Adapted and reprinted with permission from refs. 108,109. e ORR volcano plot for MGEN constructed from plotting the theoretical exchange current density (\({j}_{0}^{{\rm{theory}}}\)) versus free energies of OOH adsorption (\({\triangle G}_{{\ast }_{{\rm{OOH}}}}\)). Adapted and reprinted with permission from ref. 110, https://pubs.acs.org/doi/10.1021/ja500432h, all future permissions should be directed to the ACS. f OER volcano plot for single-metallic SACs, showing the theoretical onset potentials (\({U}_{{\rm{RHE}}}^{{\rm{onset}}}\)) versus OH adsorption free energy (\({\triangle G}_{{\ast }_{{\rm{OH}}}}\)). Adapted and reprinted with permission from ref. 108. g NRR volcano plot for C3N4 SACs constructed from plotting theoretical limiting potentials versus free energy of N adsorption (\({\triangle G}_{{\ast }_{{\rm{N}}}}\)). Adapted and reprinted with permission from ref. 111. h Selectivity plot for the NRR vs. HER for SACs constructed by plotting free energy of N adsorption (\({\triangle G}_{{\ast }_{{\rm{N}}}}\)) versus free energy of H adsorption (\({\triangle G}_{{\ast }_{{\rm{H}}}}\)). Adapted and reprinted with permission from ref. 112.
