High‐Performance Co‐MnO_x Composite Oxide Catalyst Structured onto Al‐Fiber Felt for High‐Throughput O₃ Decomposition

Abstract

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 highthroughput 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.À 1 h À 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.[a] L.

Significant Promotion of Surface Oxygen Vacancies on Bimetallic CoNi Nanocatalysts for Hydrodeoxygenation of Biomass-derived Vanillin to Produce Methylcyclohexanol

“…Interestingly, three CoNiAl-MMO samples present a reduction peak of Ni 2+ species at about 550 °C . Meanwhile, compared with CoAl-MMO (342 °C), CoNiAl-MMO samples show a reduction peak of Co 3+ to Co 2+ species at a lower temperature of 285 °C, besides a reduction peak of Co 2+ to Co 0 at about 660 °C. It illustrates that the reducibility of Ni and Co species is simultaneously improved in CoNiAl-MMO samples, because of strong interactions between Ni and Co atoms.…”

“…peak of Co 3+ to Co 2+ species at a lower temperature of 285 °C,41 besides a reduction peak of Co2+ to Co 0 at about 660 °C. It illustrates that the reducibility of Ni and Co species is simultaneously improved in CoNiAl-MMO samples, because of strong interactions between Ni and Co atoms.…”

Heterostructured Ni/NiO Nanocatalysts for Ozone Decomposition

“…The final geometric form of the catalyst is very important for practical applications, which can offer a low pressure drop in the catalytic process. For example, the microfibrously structured Co-MnO x /ns-γ-Al 2 O 3 /Al fiber (Co-MnO x -Al) catalyst system has been recently developed for high-throughput O 3 decomposition and exhibited high activity, good stability, and promising humidity resistance . Generally, the catalytically active component is prepared separately and then impregnated or coated on available substrates such as ceramic fibers, honeycomb monoliths, and metal foams .…”

“…For example, the microfibrously structured Co-MnO x /ns-γ-Al 2 O 3 /Al fiber (Co-MnO x -Al) catalyst system has been recently developed for high-throughput O 3 decomposition and exhibited high activity, good stability, and promising humidity resistance. 56 Generally, the catalytically active component is prepared separately and then impregnated or coated on available substrates such as ceramic fibers, honeycomb monoliths, and metal foams. 57 This two-step fabrication process is usually complex, and the adhesion strength between the substrate and catalyst is not very good.…”

The Adsorption of Ozone on the Solid Catalyst Surface and the Catalytic Reaction Mechanism for Organic Components

“…Moreover, Ce modified Mn−Fe composite oxides catalyzed the decomposition of organic components by ozone at room temperature and high humidity; [29d] thin‐felt Al‐fiber‐structured Co−MnO x composite oxide catalyst achieved 100 % O 3 conversion for 720 min at 25 °C under a high gas hourly space velocity of 48000 mL g cat. −1 h −1 , containing 1000±30 ppm O 3 ; [29e] the CeO 2 ‐LaMnO 3 composite could utilize light and heat to enhance ozone decomposition [29f] . In summary, for ozone adsorption and decomposition, composite catalysts not only had the advantage of multi‐site synergy to resist the effects of environmental factors, such as high humidity, causing catalyst deactivation but also improved the decomposition efficiency of ozone through photocatalysis.…”