Boosting Activity and Selectivity in H2O2 Electrosynthesis via Organic Motif-Mediated Intermediate Adsorption Optimization

Abstract

The two-electron oxygen reduction reaction (2e^- ORR) enables sustainable H₂O₂ synthesis, yet its activity and selectivity are limited by the adsorption of oxygen-containing intermediates. Herein, we developed a dual-functionalized Co-based covalent organic polymers (COPs) that synergistically enhances O₂ adsorption and optimizes ⁎OOH binding strength, thereby achieving concurrent breakthroughs in 2e^- ORR activity and selectivity. The optimized N⁺-NH-CoTAPP-BDTA delivers a remarkable 97.6% H₂O₂ Faradaic efficiency at 200.0 mA cm^-2 with a stable accumulation of 1.0 wt% H₂O₂. The in-situ generated H₂O₂ exhibits exceptional environmental remediation efficacy, achieving complete degradation of Rhodamine B (0.1 g L^-1) within 60 minutes and 100% bacterial eradication (2.41 × 10⁴ to 0 c.f.u. mL^-1) in 10 minutes. Our studies reveal an intriguing synergy between -NH- and N⁺ motifs: -NH- motifs disrupt π-conjugation to enrich electrons and accelerate O₂ activation; the N⁺ ionized skeletons induce localized charge deficiency, thus optimizing ⁎OOH binding strength. This dual-functionalization creates an adsorption-desorption equilibrium that simultaneously accelerate O₂ activation while suppressing O-O break in ⁎OOH, thus elevating both activity and selectivity. Through rational organic motif design, we simultaneously optimized the adsorption of ⁎O₂ and ⁎OOH, which establishes a paradigm for concurrently addressing the longstanding challenges of insufficient activity and selectivity in H₂O₂ electrosynthesis.