Scalable H ₂ O ₂ Production via O ₂ Reduction Using Immobilized Vanadyl Phthalocyanine

Abstract

Abstract The production of hydrogen peroxide (H 2 O 2 ) via the two‐electron oxygen reduction reaction (ORR) has emerged as a promising alternative to the conventional anthraquinone process. However, achieving selective H 2 O 2 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 H 2 O 2 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.