Chemical Identification of Catalytically Active Sites on Oxygen‐doped Carbon Nanosheet to Decipher the High Activity for Electro‐synthesis Hydrogen Peroxide

Abstract

Electrochemical production of hydrogen peroxide (H 2 O 2 )t hrough two-electron (2 e À )o xygen reduction reaction (ORR) is an on-site and clean route.O xygen-doped carbon materials with high ORR activity and H 2 O 2 selectivity have been considered as the promising catalysts,h owever,t here is still alackofdirect experimental evidence to identify true active sites at the complex carbon surface.H erein, we propose ac hemicalt itration strategy to decipher the oxygen-doped carbon nanosheet (OCNS 900 )c atalyst for 2e À ORR. The OCNS 900 exhibits outstanding 2e À ORR performances with onset potential of 0.825 V( vs.R HE), mass activity of 14.5 Ag À1 at 0.75 V( vs.R HE) and H 2 O 2 production rate of 770 mmol g À1 h À1 in flow cell, surpassing most reported carbon catalysts.Through selective chemical titration of C = O, C À OH, and COOH groups,wefound that C = Ospecies contributed to the most electrocatalytic activity and were the most active sites for 2e À ORR, which were corroborated by theoretical calculations.

A Facile “Double‐Catalysts” Approach to Directionally Fabricate Pyridinic NB‐Pair‐Doped Crystal Graphene Nanoribbons/Amorphous Carbon Hybrid Electrocatalysts for Efficient Oxygen Reduction Reaction

“…[48] In the high-resolution O 1s spectra, the NC has two peaks at 531.7 and 533.1 eV corresponding to CO and COH, respectively (Figure 2e). [52,53] Both CO and COH groups are catalytic sites for ORR, but the product is H 2 O 2 via a 2e − pathway. [52,53] In addition, the high surface charge transfer resistivity of oxygen-containing functional groups results in high overpotentials in electrochemical reaction.…”

Synergistic effect of doped nitrogen and oxygen-containing functional groups on electrochemical synthesis of hydrogen peroxide

“…After careful deconvolution with the same standard rules, four distinct regions were identified. The four peaks included CO (531.0 eV), 4,5,33 C–O–C/OC–O (532.4 eV), 33,34 C–OH (533.7 eV), 29,33,34 and physically adsorbed H 2 O/O 2 (535.8 eV). 5,34 Fig.…”

“…The four peaks included CO (531.0 eV), 4,5,33 C–O–C/OC–O (532.4 eV), 33,34 C–OH (533.7 eV), 29,33,34 and physically adsorbed H 2 O/O 2 (535.8 eV). 5,34 Fig. S13† points out the deconvolution of the O 1s peaks of N-CBMC-500, N-XBMC-500, N-GBMC-500, and N-FBMC-500.…”

“…2 Moreover, the equipment for producing H 2 O 2 is characterized by high pollution, high transportation cost, and the inability to be used on-site. 5 These characteristics do not reflect its intrinsic value of H 2 O 2 production. Therefore, the electrochemical oxygen reduction reaction (ORR) to generate H 2 O 2 has aroused great interest as a green and clean production method used on-site.…”

Surface Diels–Alder adducts on multilayer graphene for the generation of edge-enriched single-atom FeN4 sites for ORR and OER electrocatalysis

“…Fe or Co) to obtain optimal electronic and geometric structures. [14][15][16][17][18][19][20][21] More concretely, density functional theory (DFT) calculations suggested that co-doping of Fe and N in the form of possible FeN 4 sites on a graphitic substrate could be as active as Pt for O 2 adsorption and subsequent O]O bond breaking during the ORR. [22][23][24][25] In this sense, nitrogen-containing functional groups on a graphitic matrix also play a fundamental role in the performance and electronic conductivity of electrocatalytic processes.…”