A propanesulfonic acid-derivatized mesoporous SBA-15 catalyst was synthesized, characterized in terms of surface properties, and shown to have high selectivities for alcohol coupling to form ethers, specifically from methanol and isobutanol coupling to form methyl isobutyl ether with no detectable formation of butenes at temperatures <400 K. Kinetic analysis was consistent with competitive adsorption of the two alcohols onto Bronsted acid sites, with isobutanol being more strongly adsorbed on the acid sites than the methanol.