High‐Performance Co‐MnO x Composite Oxide Catalyst Structured onto Al‐Fiber Felt for High‐Throughput O 3 Decomposition

A highly active and efficient thin‐felt Al‐fiber‐structured Co‐MnO x composite oxide catalyst (named Co‐MnO x ‐Al) with unique form factor and high permeability is developed for high‐throughput catalytic decomposition of gaseous ozone (O 3 ). Thin‐sheet Al‐fiber felt (60 μm diameter; 90 vol % voidage) chips underwent a steam‐only oxidation and calcination for endogenously growing a 0.7‐μm‐thick mesoporous layer of γ‐Al 2 O 3 nanosheets along with the Al‐fiber. Cobalt and manganese were placed onto the ns‐γ‐Al 2 O 3 /Al‐fiber chips by incipient wetness co‐impregnation method. The best catalyst is the one with a Co/Mn molar ratio of 0.36 and Co‐Mn loading of 5 wt % after calcining at 500 °C (named Co‐MnO x (0.36)‐Al), being able to achieve full O 3 conversion at 25 °C for a feed gas containing 1000±30 ppm O 3 , using a high gas hourly space velocity of 48000 mL g cat. −1  h −1 ; full O 3 conversion is retained in the absence of moisture till the testing end after 720 min; in case with a relative humidity of 50 %, O 3 conversion slides from 88 % of the initial value to a flat of ∼66 % within 90 min. CoO x modification is paramount for improved formation of Mn 2+ species while leading to the highest fraction of (Mn 2+ +Mn 3+ ) in total (Mn 2+ +Mn 3+ +Mn 4+ ) and more oxygen vacancies on Co‐MnO x (0.36)‐Al catalyst surface.