Highly Efficient Electrochemical Synthesis of Hydrogen Peroxide (H2O2) Enabled by Amino Acid Glycine-Derived Metal-Free Nitrogen-Doped Ordered Mesoporous Carbon

Electrocatalytic partial oxygen reduction has been considered a more sustainable approach to the synthesis of hydrogen peroxide (H2O2), as compared with current industrial anthraquinone processes. One key research need is to explore low-cost active electrocatalysts. Here, we report a facile, solvent-free method to synthesize a metal-free nitrogen-doped ordered mesoporous carbon (N-OMC) by in situ transforming of glycine (carbon and nitrogen precursors) in the mesoporous SiO2 template (KIT-6) followed by subsequent thermal treatment at different temperatures. Among all samples, the catalyst treated at 800 °C (N-OMC-800), the nitrogen-rich carbon, exhibits outstanding structural properties and porosity, showing the dominant formation of pyrrolic-N and graphitic-N. With combined improved structural properties with the optimal ratio of N-pyrrolic/N-graphitic, P/G carbon provided an outstanding electrocatalytic activity, promoting H2O2 with high selectivity and production rate in alkaline mediums. The N-OMC-800 can achieve a faradaic efficiency (FE) of ∼100% to H2O2 at (0.6 VRHE to 0.4 VRHE) in a H-cell containing 0.1 M KOH. Furthermore, its bulk H2O2 electrosynthesis in our self-designed flow cell confirmed its practical capability by showing a remarkable H2O2 production rate of 9.43 mol gcat–1 h–1 at 0.35 VRHE and maintaining nearly 100% FE at the cathode potential of 0.6 VRHE for 12 h without any degradation.