Preparation of highly dispersed tungsten oxide on MCM-41 via atomic layer deposition and its application to butanol dehydration.

Highly dispersed tungsten oxide on MCM-41 was synthesized using a novel atomic layer deposition (ALD) method. BET, XRD, XPS, NH3-TPD, and pyridine-IR were used to study the physicochemical properties of the supported tungsten oxides. In this study, the maximum loading of tungsten oxide on MCM-41 that could be prepared using the modified ALD method was 27.0 wt%. It was confirmed that the textural properties of the mesoporous silica were maintained after tungsten oxide loading. The NH3-TPD and Py-IR results indicated that weak acid sites, mainly Lewis acid sites, were produced over the WO3/MCM-41 samples. Moreover, 2-butanol dehydration was performed to demonstrate the potential advantages of the WO3/MCM-41 catalysts. The WO3/MCM-41 catalyst with 27.0 wt% tungsten oxide loading showed the highest activity in the dehydration of 2-butanol, which was attributed to the highest overall number of acid sites among the WO3/MCM-41 catalysts. The highly dispersed tungsten oxide on MCM-41 prepared via ALD can be an effective catalyst for producing butenes through 2-butanol dehydration.