Regulating N Species in N‐Doped Carbon Electro‐Catalysts for High‐Efficiency Synthesis of Hydrogen Peroxide in Simulated Seawater

Abstract

Electrochemical oxygen reduction reaction (ORR) is an attractive and alternative route for the on‐site production of hydrogen peroxide (H2O2). The electrochemical synthesis of H2O2 in neutral electrolyte is in early studying stage and promising in ocean‐energy application. Herein, N‐doped carbon materials (N‐Cx) with different N types are prepared through the pyrolysis of zeolitic imidazolate frameworks. The N‐Cx catalysts, especially N‐C800, exhibit an attracting 2e− ORR catalytic activity, corresponding to a high H2O2 selectivity (≈95%) and preferable stability in 0.5 m NaCl solution. Additionally, the N‐C800 possesses an attractive H2O2 production amount up to 631.2 mmol g−1 h−1 and high Faraday efficiency (79.8%) in H‐type cell. The remarkable 2e− ORR electrocatalytic performance of N‐Cx catalysts is associated with the N species and N content in the materials. Density functional theory calculations suggest carbon atoms adjacent to graphitic N are the main catalytic sites and exhibit a smaller activation energy, which are more responsible than those in pyridinic N and pyrrolic N doped carbon materials. Furthermore, the N‐C800 catalyst demonstrates an effective antibacterial performance for marine bacteria in simulated seawater. This work provides a new insight for electro‐generation of H2O2 in neutral electrolyte and triggers a great promise in ocean‐energy application.

Fe-Based Deep Eutectic Solvents for Amorphous Carbon-Encapsulated Fe3O4 Nanoparticles as Electrocatalysts for H2O2 Synthesis

“…The catalytic kinetics of the ORR were further estimated by Tafel plots derived from the LSV curves (Figure c). Fe 3 O 4 @C displays a smaller Tafel slope (65 mV·dec –1 ) than FeO–Fe 3 O 4 @C (74 mV·dec –1 ) and C (77 mV·dec –1 ), indicating superior 2e – ORR kinetics for Fe 3 O 4 @C. , Furthermore, to determine the intrinsic activity of the samples, electrochemical double-layer capacitance ( C dl ) obtained by CV curves at different sweep rates (Figure S17) and electrochemical impedance spectroscopy (EIS) were investigated. Figure d illustrates that the capacitance of FeO–Fe 3 O 4 @C (0.2 mF·cm –2 ) and Fe 3 O 4 @C (0.13 mF·cm –2 ) is greater than that of C (0.04 mF·cm –2 ).…”

Optimization Strategy for Formaldehyde Removal by Carbon Cathode Electro-Fenton: Enhancement of Formaldehyde and Oxygen Co-adsorption by Rational Nitrogen Doping Types

“…According to the literature, nitrogen doping modification can improve the 2e – ORR selectivity of activated carbon materials. − In this study, cyclic voltammetry (CV) and linear scanning voltammetry (LSV) curves of four prepared activated carbon materials were measured using an electrochemical workstation. The aim was to evaluate their electrochemical properties.…”