beta-Co(OH)(2) Nanostructures with High Spin Co(II) in Distorted [CoO6] for Catalytic Ozone Decomposition

There is a high demand to synthesize ozone decomposition catalysts especially in high-space-velocity and high-relative-humidity (RH) environments. Herein, two polymorphs of cobalt hydroxide, alpha- and beta-Co(OH)(2), are synthesized and applied for ozone elimination. beta-Co(OH)(2) shows similar to 90% ozone decomposition efficiency under high space velocity (weight hourly space velocity (WHSV) = 1,200,000 mL g(-1) h(-1), 25 degrees C, 40 ppm), which is far higher than that of alpha-Co(OH)(2) (similar to 5%). beta-Co(OH)(2) has high spin Co(II) in distorted octahedral coordination caused by the Jahn-Teller effect, leading to a higher crystal field splitting energy level and thus contributing to the easier electron transfer between the ozone and catalyst. Moreover, beta-Co(OH)(2) still shows high performance (similar to 87%) even in humid conditions (RH similar to 50%, 25 degrees C, 40 ppm, WHSV = 600,000 mL g(-1) h(-1)), which is attributable to its abundant surface non-hydrogen-bonded hydroxyls weakening water molecule adsorption, providing an idea to develop highly efficient catalysts for ozone decomposition in humid environments.