Abstract
The oxygen reduction reaction (ORR) is essential for both energy conversion devices and green hydrogen peroxide (H2O2) synthesis. Whereas, it remains a challenge to efficiently tune the oxygen reduction selectivity toward the target applications. Herein, we designed two kinds of Co-N-C materials with encapsulated Co nanoparticles (Co_(NP)-N-C) and with atomically dispersed cobalt atoms strongly embedded into nitrogen-doped carbon nanotubes (Co_(SA)-N-CNTs), and successfully realized the ORR pathway transformation from four-electron (4e~-) to two-electron (2e~-) for high-performance H2O2 production. This tunability is ascribed to the modification of the atomic configuration of the Co-N-C catalyst. Remarkably, when employing Cosa-N-CNTs material as a 2e~- ORR catalyst, the assembled electrode exhibits a high H2O2 production rate of approximately 974 ± 25 mmol g_(cat)~(-1) h~(-1), along with an ultra-fast organic matter degradation performance. This work provides an efficient strategy for tuning oxygen reduction selectivity via a simple structure tuning of the materials for specific applications.
NSTL