Electrochemical hydrogen peroxide (H2O2) production (EHPP) via a two-electron oxygen reduction reaction (2e ORR) offers a promising alternative to the energy-intensive anthraquinone process. M-N-C electrocatalysts, featuring atomically dispersed transition metals and nitrogen-doped carbon, show significant EHPP efficiency. However, their full potential, especially the correlation between structural configurations and performance in neutral media, remains largely unexplored. This study synthesizes and investigates a series of ultralow metal-loading M-N-C electrocatalysts for EHPP in neutral electrolytes. CoNCB, exhibiting an asymmetric Co-C/N/O configuration, shows the highest EHPP activity and selectivity, with exceptional mass activity (6.1 × 10⁵ A gCo⁻¹ at 0.5 V vs. RHE) and H2O2 production rate (4.72 molcatalyst⁻¹ h⁻¹ cm⁻²). X-ray absorption fine structure spectroscopy and computational studies reveal the superiority of asymmetric Co-C/N/O over the common square-planar symmetric Co-N₄ configuration.

Longxiang Liu (Christopher Ingold Laboratory, Department of Chemistry, University College London, London WC1H 0AJ, UK), Liqun Kang (Department of Inorganic Spectroscopy, Max-Planck-Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany), Jianrui Feng (Christopher Ingold Laboratory, Department of Chemistry, University College London, London WC1H 0AJ, UK), David G. Hopkinson (Electron Physical Science Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, UK), Christopher S. Allen (Electron Physical Science Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, UK), Yeshu Tan (Christopher Ingold Laboratory, Department of Chemistry, University College London, London WC1H 0AJ, UK), Hao Gu (Department of Chemical Engineering, University College London, London WC1E 7JE, UK), Iuliia Mikulska (Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, UK), Veronica Celorrio (Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, UK), Diego Gianolio (Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, UK), Tianlei Wang (Christopher Ingold Laboratory, Department of Chemistry, University College London, London WC1H 0AJ, UK), Liquan Zhang (Christopher Ingold Laboratory, Department of Chemistry, University College London, London WC1H 0AJ, UK), Kaiqi Li (Christopher Ingold Laboratory, Department of Chemistry, University College London, London WC1H 0AJ, UK), Jichao Zhang (Christopher Ingold Laboratory, Department of Chemistry, University College London, London WC1H 0AJ, UK), Jiexin Zhu (Christopher Ingold Laboratory, Department of Chemistry, University College London, London WC1H 0AJ, UK), Georg Held (UK Catalysis Hub, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot OX11 OFA, UK), Pilar Ferrer (Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, UK), David Grinter (UK Catalysis Hub, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot OX11 OFA, UK), June Callison (UK Catalysis Hub, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot OX11 OFA, UK), Martin Wilding (UK Catalysis Hub, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot OX11 OFA, UK), Sining Chen (Christopher Ingold Laboratory, Department of Chemistry, University College London, London WC1H 0AJ, UK), Ivan Parkin (Christopher Ingold Laboratory, Department of Chemistry, University College London, London WC1H 0AJ, UK), Guanjie He (Christopher Ingold Laboratory, Department of Chemistry, University College London, London WC1H 0AJ, UK)