Cobalt Nanoparticles Induced Strong Metal–Support Interactions for Industrial-Relevant Current Density Electrosynthesis of Hydrogen Peroxide

Carbon-based catalysts show promising potential for H2O2 electrosynthesis via a two-electron oxygen reduction reaction. General approaches typically involve introducing heteroatoms or creating defects in the graphitic carbon framework to enhance the catalytic activity and H2O2 selectivity. However, these modifications inevitably compromise electrical conductivity, making them difficult for large-current-density electrosynthesis. To address this limitation, we developed a cobalt-activated, nondestructive metal–support interaction (MSI) strategy. By constructing a carbon-encapsulated Co nanoparticle catalyst (Co@OC), we established a strong MSI between Co and the carbon support that generated active sites without disrupting the graphitic structure. Experimental results indicated that Co-induced charge polarization generated carbon active sites while preserving the high conductivity of graphitic carbon. It enabled the Co@OC catalyst to achieve ∼95% Faradaic efficiency for H2O2 production at 900 mA cm–2 with a yield of 29.6 mol h–1 gcat–1, which was markedly higher than the carbon catalysts lacking Co activation. Density functional theory calculations elucidated that the encapsulated Co nanoparticles induced positive charges on adjacent carbon atoms via MSI, with this electronic modulation simultaneously facilitating O2 adsorption and optimizing the *OOH intermediate binding energy to boost both catalytic activity and H2O2 selectivity. A scaled-up system with a 500 cm2 electrode produced directly applicable 3 wt % H2O2 at a rate of 477 mmol h–1 (25 A) and an operating cost of $0.023 kg–1, demonstrating its economic competitiveness. Our work establishes a promising strategy for activating carbon-based materials through MSI with metal nanoparticles, offering valuable design principles for efficient H2O2 electrosynthesis catalysts.