DME can be produced directly from syngas over bifunctional Cu-based catalysts or synthesized by methanol dehydration over solid acid catalysts at 200–450 °C in a pressure of up to 18 atm [8], [9], [10], [11] and [12]. Among different kinds of solid acids used for methanol dehydration, H-ZSM-5 and γ-Al2O3 have been investigated intensively both in laboratory and commercial scales. H-ZSM-5 has been reported to be more active than γ-Al2O3, but rapid deactivation occurs on its strong acidic sites due to the generation of undesirable hydrocarbons [13] and [14]. On the other hand, γ-Al2O3 is more selective to DME, but it has some disadvantages including low activity and rapid deactivation in the presence of water.