Highly efficient Mn2O3 catalysts derived from Mn-MOFs for toluene oxidation: The influence of MOFs precursors

Abstract

The effect of Mn-MOFs precursors (Mn-MIL-100, Mn-MOF-74 and Mn-BTC) on the performance of Mn2O3 catalysts pretreated with different atmosphere (Ar, O2 and O2 after Ar treatment) for toluene oxidation is investigated in this work, respectively. The characteristics of the catalysts are investigated by using scanning electron microscope (SEM), the X-ray diffraction (XRD), Brunauer Emmett Teller (BET), X-ray photoelectron spectroscopy (XPS) and H2 temperature programmed reduction (H2-TPR). It is observed that Mn-MIL-100 pretreated with Ar and then with O2 (Mn-100-Ar-O) shows better catalytic activity for toluene oxidation than Mn-MIL-100 pretreated with single Ar or O2. Furthermore, MOFs precursors have strongly influence on the structure and performance of Mn2O3 catalysts. The order of catalytic activity is as follows: Mn-100-Ar-O > Mn-BTC-Ar-O > Mn-74-Ar-O. In addition, Mn-100-Ar-O exhibits high stability, circulation performance and water resistance. The catalytic performance of Mn-100-Ar-O is obviously improved with the better reduction at low-temperature and the increase of surface molar ratio of Mn3+/Mn4+ and Oads/Olatt.