We have firstly examined how the presence of ethyl benzoate (EB) close to the Ti species affects its stability and charge density on single crystal MgCl2 (110) and (100) surfaces by periodic density functional calculations. The energetic modification upon the coadsorption of EB and the Ti species was quite slight on both the (110) and (100) surfaces, which implies the random placement of these adsorbents on the support. The electron transfer from EB to the support enhanced the electron negativity of the Ti species on the (110) surface. In contrast, the electron that was donated from EB to the support never moved into the Ti species on the (100) surface. These results suggest that the addition of EB into the catalyst system introduces coadsorption-induced active sites selectively on the (110) surface.