Pre-embedding an energetic metal–organic framework to create interconnected pore structures in nitrogen-doped carbon for green and effective hydrogen peroxide electrosynthesis

Abstract

The two-electron (2e⁻) oxygen reduction reaction (ORR) is a green way to produce hydrogen peroxide (H₂O₂). However, the ORR occurs at the gas–liquid–solid interface, and the active sites in the electrocatalyst are buried, preventing them from taking part in the reaction and lowering the reaction efficiency. To boost the efficacy of the 2e⁻ ORR, the template method is widely used to construct pores to optimize the mass transfer process; however, the post-treatment using strong acids and bases will inevitably produce toxic pollutants. Herein, an interconnected pore structure was produced in the carbon electrocatalyst by utilizing an “inside-out” energy release pore-making strategy triggered by the detonation of an energy metal–organic framework (EMOF). In order to expose additional active sites for the 2e⁻ ORR, the pre-buried EMOF releases large amounts of gases, generates shocks to the carbon electrocatalyst during the pyrolysis process, and avoids acid–base post-treatment. The electrocatalyst demonstrated a remarkable H₂O₂ yield of 74.98 mg h⁻¹ and an H₂O₂ selectivity of over 95%. It is worth noting that the electrocatalyst can consistently produce H₂O₂ for more than 42 hours with negligible performance degradation. This facile and green strategy can be applied to modify the pore structure of the electrocatalysts to achieve the desired 2e⁻ ORR performance, thus enabling the green and efficient electrosynthesis of H₂O₂.