The adsorption mechanisms for aliphatic and aromatic sulfur compounds onto Ag/TiOx-Al2O3 (10 wt % Ag; Ti/Al = 1:4.4 by weight) adsorbent were investigated in this paper. The mesoporous mixed-oxide-supported silver adsorbent demonstrated promising sulfur adsorption capacities (similar to 10 mg of S/g of adsorbents) from liquid hydrocarbon fuels [JP5, JP8, and off-road diesel (ORD)]. However, its performance was significantly hindered by the presence of non-sulfur aromatics. In situ infrared (IR) spectra of TiOx-Al2O3 and Ag/TiOx-Al2O3 samples treated with various model revealed dissociative chemisorption pathways for different sulfur species. The aliphatic (1-butanethiol and diethyl sulfide) an aromatic (thiophene, benzothiophene, dibenzothiophene, and 4,6-dimethyldibenzothiophene) sulfur compounds underwent dissociative and reactive adsorption on the surface acid sites at room temperature. The surface hydroxyl groups adsorbed the sulfur aromatics primarily via hydrogen bonding (3100-3400 cm(-1)), and possible dissociated products were saturated/partially saturated aliphatic compounds. The presence of non-sulfur aromatics (benzene) reduced the sulfur adsorption capacity (similar to 18% for Ag/TiOx-Al2O3) because of its competitive adsorption on the adsorbent via pi interactions.