Abstract:

In this study, we regulated copper loading and the atomic ratio of Cu/Mn and investigated the influence on interaction of the active species of Cu-Mn composite oxide catalyst supported on TiO₂ (Cu_xMn_y/ TiO₂). The results indicate that 15% (w, mass fraction) copper loading and a 1 : 1 atomic ratio of Cu/Mn favors formation of analogous Cu-Mn spinel (Cu_1.5Mn_1.5O₄). With increasing loading of copper, oxygen transfers from the lattice oxygen species to defect oxygen. The changes in copper loading and the Cu/Mn atomic ratio have a large influence on the interaction between the active components and the catalytic activity. We found that 90% n-hexanal can be degraded by Cu₁₅Mn₁₅/TiO₂ at 225 ℃ (T₉₀). The excellent performance of Cu₁₅Mn₁₅/TiO₂ is attributed to the higher contents of Cu²⁺ and O_ads, which can achieve a dual redox process with Mn²⁺ in Cu₁₅Mn₁₅/TiO₂. The analogous Cu-Mn spinel active ingredient can maintain high catalytic stability by redox cycles.

Key words: Copper loading capacity, Cu/Mn atomic ratio, Cu_xMn_y/TiO₂, Active component, Catalytic oxidation, n-Hexanal