Tailoring oxygenated groups of monolithic cobalt-nitrogen-carbon frameworks for highly efficient hydrogen peroxide production in acidic media

Electrochemical synthesis has emerged as a promising alternative method for industrial production of hydrogen peroxide (H2O2). Although transition metal-nitrogen-carbon moieties have been regarded as efficient catalysts for oxygen reduction reaction (ORR), they are generally established for four-electron (4e−) pathway, rather than two-electron (2e−) one for selective generation of H2O2. Herein, we propose a strategy to achieve cobalt-carbon hybrids with high 2e− selectivity for H2O2 production in acidic media via tailoring their surface structure and coordination environment. The correlation between 2e− ORR selectivity of the fabricated monolithic electrodes, i.e. Co nanoparticles embedded in N-doped oxo carbon framework (CoNCF), and their oxygen-containing functional groups is revealed. In particular, an excellent H2O2 selectivity over 91 % in 0.05 M H2SO4 is achieved, which exceeds most of previously reported 2e− ORR electrocatalysts. Moreover, a sterilization system for water disinfection is constructed, demonstrating potential practical applications. The smart design of multi-active sites and porous monolithic architecture opens a new avenue for preparing advanced electrode for H2O2 generation and other environment/energy-related systems.