Rational design of highly selective nitrogen-doped Fe_2O_3-CNTs catalyst towards H_2O_2 generation in alkaline media

摘要

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. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.