Humidity-resistant catalytic ozone decomposition through water transport control in dual-confined nanospaces

Catalytic ozone decomposition has proven to be the most efficient and cost-effective method for mitigating O3 pollution, while further advancement in this field is hindered by the unsatisfactory humidity resistance and poor long-term stability of current catalysts. This study employs water transport confinement and electronegativity modulation in confined nanospaces of catalyst to address these challenges. We design a hydrophilic dual-space confined CoO mesocrystal (mesoCoO-P5) featuring hierarchically organized 0D nanocavities and 2D interlayers. The densely networked hydrogen bonds on the hydrophilic confined surface restrict water mobility, thereby preventing catalyst poisoning from water accumulation. Meanwhile, the presence of electronegative hydroxyl groups on catalyst promotes the conversion of peroxide intermediates into O2. The mesoCoO-P5 catalyst achieves stable ozone decomposition for over 24 hours under 70% relative humidity. High activity is maintained at −5oC and an ultrahigh space velocity of 4000 L·g−1 h−1, while accelerated ozone decomposition performance is demonstrated in a 3 m3 indoor room and under dust-coexisting conditions. This work establishes confinement engineering as a novel paradigm for enhancing anti-poisoning properties in the design of robust environmental catalysts. Ozone-removal catalysts often lose activity in humid air, limiting durable pollution control. This study confines water and tunes surface chemistry in cobalt oxide, enabling stable ozone breakdown under harsh conditions.