Abstract
The continuous on-site production of H2O2 using an inexpensive metal catalyst based electrochemical approach as the alternative of the widely used complex anthraquinone process is particularly promising. Although tremendous progress has been made in recent years towards developing oxygen reduction reaction (ORR) catalyst for H2O2 production, fabricating highly active, selective, and stable H2O2 catalyst that works at high pH is always the challenge. Here, we describe a rationally designed non-precious metal-based nitrogen-doped Fe2O3-carbon nanotubes (NC@Fe2O3-CNTs) catalyst, which not only exhibits high ORR activity and low overpotential but also shows a unique selectivity towards H2O2 generation (97.3%) in alkaline media. Moreover, the NC@Fe2O3-CNTs catalyst retains a much higher relative current after continuous operation for 10 h, as compared to commercial Pt/C catalyst. The optimized NC@Fe2O3-CNTs shows the superior overall performance of H2O2 generation as compared to the present catalysts under high pH. The catalytic mechanism analysis indicates that the nitrogen species, Fe chemical states, oxygen vacancies and CNTs skeleton play important roles in improving the selectivity and current density of H2O2 generation.
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•Nitrogen-doped carbon wrapped Fe2O3-CNTs composite is synthesized by a facile and controllable method.•The NC@Fe2O3-CNTs catalyst exhibits high activity, selectivity and long term stability on ORR for H2O2 generation.•A synergistic effect between the N-doped carbon and Fe2O3 clusters is proved to dominate the superior catalytic performance.•A reasonable catalytic mechanism is proposed based on experimental results.