Scalable H2O2 Production via O2 Reduction Using Immobilized Vanadyl Phthalocyanine

The production of hydrogen peroxide (H₂O₂) via the two-electron oxygen reduction reaction (ORR) has emerged as a promising alternative to the conventional anthraquinone process. However, achieving selective H₂O₂ production at practically relevant current densities (i.e., ampere-level) remains challenging due to significant selectivity deterioration at high rates. In this study, we develop a composite catalyst by immobilizing vanadyl phthalocyanine (VOPc) on carbon nanotube (CNT) substrates and evaluate its performance under conditions relevant to practical ORR electrolysis. Encouragingly, the VOPc/CNT catalyst composite achieves a high ORR current density of up to 3.5 A cm⁻² with over 90% selectivity toward H₂O₂ in acidic media. Through various in situ characterizations and theoretical calculations, we reveal that the structural integrity of the vanadium catalytic center in VOPc plays a pivotal role in stabilizing *OOH adsorption and impeding O─O cleavage under high cathodic potentials, which is critical for achieving high H₂O₂ selectivity at elevated current densities.