Preparation and catalytic performance of OMS-2/Al₂O₃/cordierite monolithic catalyst

Monolithic catalysts for catalytic combustion of dimethyl ether (DME) were prepared by a dip-coating method using Al₂O₃/cordierite as support and manganese oxide octahedral molecular sieve (OMS-2) as active component. The effect of different types of organic polymer binder and the coating times of active component on the performance of DME combustion were investigated. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), hydrogen temperature-programmed reduction (H₂-TPR) and oxygen temperature-programmed desorption (O₂-TPD) techniques. The results showed that the best catalyst was the one using methoxy polyethylene glycol (MPEG) as the coating binder by one-time coating. The active component OMS-2 was in a cluster form and homogeneously dispersed on the surface of the support because of the strong interaction between OMS-2 and Al₂O₃ coating. The Al₂O₃ coating could significantly improve the surface area of catalysts, and thus enhance the activity performance. The highest catalytic activity for DME combustion with a complete combustion temperature (t₉₀) of 257 ℃ was obtained.