The acrylonitrile adsorption over Pd/SiO2 and PdSn/SiO2 catalysts wasprepared by "Solvated Metal Atom Dispersion" (SMAD) and analyzed by DRIFTS FTIR are studied. The catalysts were used in pellets and treated with dry N2(g) flow inside a flask in contact with the acrylonitrile vapours for 6 h. A change in the adsorption capacity of acrylonitrile with the increase in Sn content in the catalysts by following the C<FONT FACE=Symbol>º</FONT> N IR band was studied. The decrease in the acrylonitrile adsorption produced a decrease in the hydrogenation rates of acrylonitrile and an increase in the hydrogenation selectivity to obtain allylamine, mainly due to a greater interaction of C<FONT FACE=Symbol>º</FONT> N with Sn