Breaking planar constraints: Curvature-tailored Co-N-C electrocatalysts for high-efficiency proton exchange membrane H2O2 production

Advancing the two-electron (2e - ) oxygen reduction reaction (ORR) in acidic media is pivotal for sustainable, on-demand hydrogen peroxide (H 2 O 2 ) production, but remains challenged by insufficient activity/selectivity at industrially relevant high current densities. We present a breakthrough catalyst design featuring cobalt atomic sites embedded in curved nitrogen-doped carbon layers (c-Co-N-C). This architecture achieves nearly 90 % H 2 O 2 selectivity across a wide potential window, delivering 11.70 mol g⁻¹ h⁻¹ productivity at 300 mA cm −2 with 80 % Faraday efficiency in flow cell tests. Particularly, the catalyst maintains a stable 300 mA cm −2 operation under 1.9 V cell voltage (surpassing prior-art systems by 0.2 V) for 120 h in a PEM electrolyzer, producing pure-phase H 2 O 2 (4.1 wt%). Through integrated experimental and computational analysis, we reveal two complementary enhancement mechanisms: first, the finite element simulations quantify the enhanced interfacial electric field that concentrates protons and dissolved oxygen; then, the density functional theory (DFT) calculations indicate a downshift in Co d -band center optimizes *OOH adsorption while suppressing O-O bond cleavage. This work establishes curvature engineering as a universal design strategy for advanced catalysts through controlled structural modification, opening new pathways for sustainable chemical synthesis.