A comprehensive review of mechanism-based catalyst design and applications for electrochemical ozone production

Ozone (O₃) is a green oxidant with significant potential for wastewater treatment, and thus, its production has been extensively studied over the past few decades. Among various ozone generation methods, electrochemical ozone production (EOP) has emerged as a promising alternative to conventional approaches, enabling direct ozone generation in aqueous media and facilitating modular integration into wastewater treatment systems. However, the inherently high oxidative potentials required for the EOP pose significant challenges in achieving both selective ozone generation from water and long-term catalyst stability. This review provides a comprehensive and mechanistically structured overview of recent electrocatalyst design for the EOP across various material types, categorized by the underlying reaction mechanisms: lattice oxygen mechanism (LOM), adsorbate evolution mechanism (AEM), and five-membered cycle mechanism (FMM). In addition, recent advances in water electro-ozoniser device engineering and their integration into wastewater treatment systems are discussed, highlighting the potential of EOP-driven electrochemical advanced oxidation technologies.