Active Edge‐Site‐Rich Carbon Nanocatalysts with Enhanced Electron Transfer for Efficient Electrochemical Hydrogen Peroxide Production

Abstract

A highly efficient, metal‐free carbon nanocatalyst is presented that possesses abundant active, oxygenated graphitic edge sites. The edge site‐rich nanocarbon catalyst exhibits about 28 times higher activity for H2O2 production than a basal plane‐rich carbon nanotube with a H2O2 selectivity over 90 %. The oxidative treatment further promotes the H2O2 generation activity to reach close to the thermodynamic limit. The optimized nanocarbon catalyst shows a very high H2O2 production activity, surpassing previously reported catalysts in alkaline media. Moreover, it can stably produce H2O2 for 16 h with Faradaic efficiency reaching 99 % and accumulated H2O2 concentration of 24±2 mm. Importantly, we find that the heterogeneous electron transfer kinetics of the carbon‐based catalyst is closely related to the electrocatalytic activity, suggesting that first outer‐sphere electron transfer to O2 is an important step governing the H2O2 production rate.

A Defect‐rich N, P Co‐doped Carbon Foam as Efficient Electrocatalyst toward Oxygen Reduction Reaction

“…The XRD pattern of NG-1000 exhibits a broad and negatively shifted peak (25.4°) from the (002) plane of graphite, indicating the exist of graphitic layers with relative small grain size and larger interplanar distance due to the presence of foreign atoms. [24] Compared with the amorphous nature of G-1000 and PG-1000, the enhanced degree of graphitization would be ascribed to the introduction of electron-rich nitrogen from urea, leading to an enhanced electroconductivity for further electrocatalysis.…”

Recent Progress on Carbonaceous Material Engineering for Electrochemical Hydrogen Peroxide Generation

“…Sa et al [31] also reported high activity for H 2 O 2 production on carbon nanomaterials with enriched oxygenated carbon edges. Zhou et al [32] studied activated carbon (AC) and revealed that the oxygen-containing groups on the AC function as oxygen reduction reaction sites for H 2 O 2 electrogeneration.…”

Catalyst Design for Electrochemical Oxygen Reduction toward Hydrogen Peroxide

“…This edge-enriched nanocarbon catalyst exhibits about 28 times higher activity for H 2 O 2 production than a basal plane-rich carbon nanotube (CNT) with a H 2 O 2 selectivity over 90%. [73] With the aid of Tafel slope and electrochemical impedance spectroscopic analysis, the authors pointed out that the first electron transfer ability from carbon to O 2 molecule (known as O 2 activation) is a prime determinant of the ORR activity. Chorkendorff et al screened seven commercially available carbon materials for 2e − ORR and revealed that H 2 O 2 selective materials have higher contribution from the C1s peak component correlated with aliphatic-type defects and edge carbon atoms, as opposed to intact graphitic carbon motifs.…”

“…Reproduced with permission. [73] Copyright 2018, Wiley-VCH. b) Representative TEM image of mesoporous nitrogen-doped carbon (MNC).…”