Boosting the catalytic performance of MnOx in acetone oxidation by weakening the MnO bond strength

Abstract

Manganese oxides (MnO_x) exhibit considerable potential in the catalytic degradation of volatile organic compounds (VOCs) due to their excellent catalytic activity, superior stability and economic cost. In this work, a two-step calcination strategy was developed to prepare MnO_x/CeO₂ catalysts with low MnO bond strengths and highly active lattice oxygens. The obtained Mn₄Ce₁-NA after the optimization has a smaller grain size, enhanced specific surface area and weakened MnO bonds, which is attributed to the in situ restriction of the manganese oxides by the two-step calcination. Moreover, the entrance of Ce into the MnO_x lattice further weakened the MnO bonds, leading to superior low-temperature reducibility and lattice oxygen activity, which effectively promoted the catalytic activity of the catalysts. The optimal samples displayed outstanding acetone degradation performance, capable of completing 90 % acetone conversion at 172 °C. The catalyst also exhibits excellent stability, with the conversion of acetone maintained at around 95 % for 64 h. This work contributes to a deeper understanding of reactive oxygen species in the catalytic oxidation of VOCs, while providing a new strategy for the rational design of efficient catalysts for the oxidation of VOCs.