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

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 (& AP;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. The synthesized graphite nitrogen doped carbon material delivers an attracting 2e- ORR catalytic activity in 0.5 m NaCl simulated seawater solution, corresponding to a high H2O2 selectivity (& AP;95%), preferable stability and H2O2 production amount up to 631.2 mmol g-1 h-1. Additionally, the prepared catalyst demonstrates an effective antibacterial performance for marine bacteria in simulated seawater.image