Mesoporous Al-Ti oxide composites with molar %Ti of 3, 5, 10, and 20 as well as pure gamma-alumina were prepared using a template-free sol-gel method in the absence of a catalyst. The prepared composites were characterized by powder XRD, FTIR spectroscopy and N-2 adsorption for BET surface area and porosity measurements. The composites and the pure alumina possessed relatively high surface areas, 350-410 m(2)/g, and high porosities after calcination at 500 degrees C. FTIR spectroscopy was employed to study the products of the catalytic dehydration of methanol to dimethyl ether, DME, over the prepared catalysts at reaction temperatures between 180 and 300 degrees C. Compared with pure gamma-alumina, the Ti-modified alumina with %Ti < 10 showed higher catalytic activity in the methanol dehydration and better selectivity to DME. Composites with %Ti of 3 and 5 showed the highest activity at relatively lower temperatures than the other catalysts where they showed their highest activity at 190 and 200 degrees C, respectively. The activity of all studied catalysts slightly decreased as the temperature was raised to 300 degrees C and dropped considerably when the temperature was decreased to 180 degrees C. However, the activity of Al-Ti-3 dropped only slightly at both temperatures. The selectivity to DME was dependent on the reaction temperature where 100% DME selectivity was obtained at temperatures <= 220 degrees C and as the temperature was raised to 300 degrees C, some CH4 and CO2 formed on the account of DME. (c) 2011 Elsevier Ltd. All rights reserved.