Hydrodechlorination was performed in water/ethanol mixtures over organosilane-grafted Rh/SiO2 catalysts. All catalysts in which organosilanes were covalently connected onto silica supports promoted hydrodechlorination, which may be attributed to the presence of a hydrophobic zone on the catalyst surfaces. Additional aromatic pi-pi interactions between the 4-tolylsilyl substituent in the catalyst and the aromatic ring of p-chloroacetophenone may be important for the activity of the most active Rh/SiO2-TS catalyst that was produced via silylation using trichloro-4-tolylsilane.