MnOx-CeO2 catalyst derived from metal-organic frameworks for toluene oxidation

Abstract

Abstract Metal-organic frameworks (MOF) are recently emerging as versatile precursors to fabricate functional MOF-derived materials for catalytic reaction. Herein, MnOx-CeO2-MOF and MnOx-MOF catalysts derived from MOF were prepared via in situ pyrolysis of MOF-74 precursor. In comparison, MnOx-CeO2-CP and MnOx-D catalysts were also synthesized by co-precipitation and thermal decomposition of MnOOH, respectively. The catalytic activity of toluene oxidation was in the order of MnOx-CeO2-MOF > MnOx-MOF > MnOx-CeO2-CP > MnOx-D, and the MOF-based catalysts were superior to MnOx-CeO2-CP and MnOx-D catalysts. The incorporation of Ce into MnOx resulted in the high surface area, abundant oxygen vacancies, good low-temperature reducibility, excellent oxygen mobility and high surface Mn4+ content, where the surface Mn4+ played a crucial role in the enhanced catalytic activity of toluene oxidation. MnOx-CeO2-MOF catalyst exhibited the T50 and T90 values of 210 and 220 °C and apparent activation energy (Ea) of 82.9 kJ/mol, which were lower than thoese of other catalysts.