Building and identifying highly active oxygenated groups in carbon materials for oxygen reduction to H2O2

Abstract

The one-step electrochemical synthesis of H 2 O 2 is an on-site method that reduces dependence on the energy-intensive anthraquinone process. Oxidized carbon materials have proven to be promising catalysts due to their low cost and facile synthetic procedures. However, the nature of the active sites is still controversial, and direct experimental evidence is presently lacking. Here, we activate a carbon material with dangling edge sites and then decorate them with targeted functional groups. We show that quinone-enriched samples exhibit high selectivity and activity with a H 2 O 2 yield ratio of up to 97.8 % at 0.75 V vs. RHE. Using density functional theory calculations, we identify the activity trends of different possible quinone functional groups in the edge and basal plane of the carbon nanostructure and determine the most active motif. Our findings provide guidelines for designing carbon-based catalysts, which have simultaneous high selectivity and activity for H 2 O 2 synthesis.

Honeycomb Carbon Nanofibers: A Superhydrophilic O2‐Entrapping Electrocatalyst Enables Ultrahigh Mass Activity for the Two‐Electron Oxygen Reduction Reaction

“…Significantly, theoretical results indicate that rich active sites exist for the adopted models, which are near the vertex of the volcano plots (corresponding to the thermodynamic equilibrium potential (0.70 V)). Among all the adsorption sites, A2‐3, A4‐3, and A4‐10 display the highest activity with the Δ G OOH* values of ≈4.21, 4.21, and 4.23 eV, respectively, which comparable with or superior to the previous catalysts [7, 16, 24, 36, 37] . Moreover, note that the three sites located near the edge of AGNR and simultaneously at the intersection of pentagon and heptagon (Figure S15).…”

Carboxyl‐Dominant Oxygen Rich Carbon for Improved Sodium Ion Storage: Synergistic Enhancement of Adsorption and Intercalation Mechanisms

“…As compared with C1600 and C1600‐M‐R, C1600‐M exhibits an unique peak located at 1712 cm −1 and meanwhile the enhanced peak at around 1250 cm −1 , both of which can be exclusively assigned to OCOH (Table S5, Supporting Information). [ 49 ] The combined XPS and FTIR characterizations solidly reveal that CO 2 ‐participated ball milling treatment could not only significantly improve the oxygen content but also precisely modify the oxygen‐containing group forms, endowing the resulting C1600‐M with both an extremely high oxygen percentage (20.12 at%) and dominant carboxyl groups. Similarly, C x ‐M samples obtained at other prepyrolyzed temperatures (800–1600 °C) also show different degrees of improvements in the oxygen contents with respect to the C x samples without postmechanochemical treatment, as depicted in Figure 2h and Figures S6–S9 (Supporting Information), demonstrating the universality of this method.…”

A Review on Challenges and Successes in Atomic-Scale Design of Catalysts for Electrochemical Synthesis of Hydrogen Peroxide

“…The field is still growing in this direction. A recent combined experimental computational study by Han et al 77 shows that quinone functional groups in the edge of carbon nanostructure exhibit high selectivity and activity for 2e-ORR.…”