Abstract: Manganese oxide octahedral molecular sieve (OMS-2)/cordierite monolithic catalysts were prepared by a coating method using poly(vinyl alcohol) (PVA) or poly(ethylene glycol) (PEG) as the binders. The catalysts were characterized by thermogravimetry-differential thermal analysis, scanning electron microscopy, X-ray diffraction, H2 temperature-programmed reduction (H2-TPR), and O2 tempera-ture-programmed desorption (O2-TPD). The catalytic activity of the catalysts in dimethyl ether (DME) combustion was evaluated. OMS-2 could be loaded on the cordierite with good adhesion stability by the coating method. OMS-2 was in a cluster form and was homogeneously dispersed on the surface of the support. The O2-TPD and H2-TPR results showed that the monolithic catalysts were rich in facile lattice oxy-gen and can activate oxygen and be easily reduced by H2, which led to excellent performance in the DME catalytic combustion. The catalyst with 3% PVA-1799 showed the highest catalytic activity for DME combustion with a light-off temperature (T10) of 169 oC and a complete combustion temperature (T90) of 243 oC. The T90 was raised to 302 oC over the used catalyst after being recalcined at 550 oC for 5 h, but the catalytic activity remained stable after nearly 100 h on stream with recycling 9 times. This indicated that the catalyst was recyclable.

Key words: manganese oxide, binder, monolithic catalyst, dimethyl ether, catalytic combustion