Fig. 4: Local H+ regulation for acidic 2e-ORR and free energy diagrams. | Nature Communications

Fig. 4: Local H+ regulation for acidic 2e-ORR and free energy diagrams.

From: Regulating active hydrogen supply and intermediate binding for pH-universal H2O2 electrosynthesis at ampere-level current density

Fig. 4: Local H+ regulation for acidic 2e-ORR and free energy diagrams.

Local pH value (a) and adsorbed-K+ concentration (b) on 0SCNT, 0.4SCNT, and 0.9SCNT surfaces during acidic 2e-ORR. c FEsH2O2 of 0SCNT, 0.4SCNT and 0.9SCNT at 0.1 M H2SO4 or 0.1 M H2SO4 + 0.1 M K2SO4 (1.5 A cm−2). d Representative snapshots for H2O, H+ and K+ distribution on SO3H-functionalized carbon surface at 0.1 M H2SO4 and 0.1 M H2SO4 + 0.1 M K2SO4. e Radial distribution function of K+ and H2O on SO3H-functionalized carbon surface at 0.1 M H2SO4 + 0.2 M K+. f H2O density on SO3H-functionalized carbon surface at 0.1 M H2SO4 and 0.1 M H2SO4 + 0.2 M K+. g Schematic diagram of acidic 2e-ORR on 0SCNT and 0.9SCNT. h Free energy profiles of 2e-ORR on carbon network, S-doped carbon, and SO3H-functionalized carbon. i Energy barriers for 2e-ORR and 4e-ORR. Error bars represent the standard deviation from three independent measurements. All the potentials have not been iR-corrected. Source data for the figure are provided as a Source data file.

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