Co-doped cryptomelane-type manganese oxide in situ grown on a nickel foam substrate for high humidity ozone decomposition.

Monolithic catalysts with excellent O catalytic decomposition performance were prepared by in situ loading of Co-doped KMnO on the surface of nickel foam. The triple-layer structure with Co-doped KMnO/NiMnO/Ni foam was grown spontaneously on the surface of nickel foam by tuning the molar ratio of KMnO to Co(NO)·6HO precursors. Importantly, the formed NiMnO structure between KMnO and nickel foam during in situ synthesis process effectively protected nickel foam from further etching, which significantly enhanced the reaction stability of catalyst. The optimum amount of Co doping in KMnO was available when the molar ratio of Mn to Co species in the precursor solution was 2:1. And the Mn2Co1 catalyst had abundant oxygen vacancies and excellent hydrophobicity, thus creating outstanding O decomposition activity. The O conversion under dry conditions and relative humidity of 65%, 90% over a period of 5 hr was 100%, 94% and 80% with the space velocity of 28,000 hr, respectively. The in situ constructed Co-doped KMnO/Ni foam catalyst showed the advantages of low price and gradual applicability of the preparation process, which provided an opportunity for the design of monolithic catalyst for O catalytic decomposition.