The interaction of the various hydroxyl groups on the Al2O3 surface with a bifunctional adsorbate, 2-chloroethylethyl sulfide, was studied by transmission infrared spectroscopy. Al2O3 has five unique Al-OH groups, differentiated by their coordination to the surface, which give independent AlO-H stretching modes. Monitoring intensity changes in these modes as 2-chloroethylethyl sulfide (CEES)molecules diffuse into the porous structure of alumina shows distinctly different stages of surface diffusion and reaction at the Al-OH groups. Three sequential steps have been separated by studies at low temperature, where the rate of the processes was kinetically retarded to allow observation. The final stage of the GEES interaction with the surface occur when the GEES molecules adsorbed on the surface via the sulfide moiety at Al3+ Lewis acid sites undergo a hydrolysis reaction with the neighboring basic AI-OH groups.