Carbon and Oxygen-Doped Phosphorus Nitride (COPN) for Continuous Selective and Stable H₂O₂ Production

Carbon and oxygen-doped phosphorus nitride (COPN) materials were synthesized via a template-assisted chemical vapor deposition (CVD)-like method. The COPN catalysts exhibited remarkable 2e(-) oxygen reduction reaction selectivity for H2O2 production across various pH environments, with COPN-3 displaying the highest selectivity up to 93.2%. Through optimization under continuous flow conditions using a flow cell, COPN-3 achieved a cumulative H2O2 concentration of up to 8 wt % with a remarkable Faraday efficiency of 99% and production rates of 17,670 mmol h(-1) g(catalyst)(-1) (basic electrolyte) and 25,758 mmol h(-1) g(catalyst)(-1) (neutral electrolyte). The catalyst maintained stable H2O2 production during a 70 h chronoamperometry, demonstrating its viability for practical electrocatalytic H2O2 production. Furthermore, a proof concept for utilizing the H2O2 generated under continuous flow conditions was demonstrated through an in situ oxidative degradation of various organic dyes. These results highlighted the promising electrocatalytic properties of COPN for practical H2O2 production and its versatility in practical applications.