Electrocatalytic production of H2O2 using COF particle electrodes with Co-Ni bimetallic sites

Hydrogen peroxide (H ₂ O ₂ ) is a common and important oxidizing agent, which is widely used in environmental protection fields. Electrochemical technology is the sustainable method for generating H ₂ O ₂ . In this study, a bimetallic Ni-Co site-loaded COF framework catalyst Co@phthalocyanine(PcNi)-tetrahydroxybenzene (THB) was synthesized, which was used as the particle electrodes in electrocatalytic hydrogen peroxide (H ₂ O ₂ ) generation systems. Scanning electron microscope (SEM) images showed the Co@PcNi-THB particle electrodes featured the porous structure. The electrochemical active area of Co@PcNi-THB increased to (3.97 mF/cm ² ), which was 2.39 times higher than that of PcNi-THB catalyst (1.66 mF/cm ² ). The maximum H ₂ O ₂ yield of 3340 µmol/g was obtained with the addition of Co@PcNi-THB catalyst content of 10 mg, current density of 15 mA/cm ² , pH 11.03, continuous stirring at 200 r/min using a magnetic stirrer, and 0.1 M Na ₂ SO ₄ electrolyte. The acidic atmosphere, Cl ⁻ and NO ₃ ⁻ ions have the inhibitory effect on the H ₂ O ₂ yields. After five cycles of Co@PcNi-THB, the H ₂ O ₂ production decreased to 3153 µmol/g, and the retention ratio of Co in Co@PcNi-THB reduced to 94%. The synergistic Co-Ni effect generated by the introduction of the metal Co enhanced the two-electron Oxygen Reduction Reaction (2e ⁻ ORR) process. This study provides new insights for designing particle electrodes with bimetallic atomic synergistic effects.