Adsorption isotherms for the single-component and multicomponent adsorption of o-nitrophenol
hydrogenation reaction species (viz. o-nitrophenol, o-aminophenol, and water) from their
methanol solution on Pd−carbon (4.6 wt % Pd) catalyst have been measured at the temperatures
(278−308 K) at which the hydrogenation reaction is carried out. Both the single and binary
adsorption data could be fitted well to Langmuir type adsorption equations. However, the
Freundlich−Langmuir equation gives a better fit to the binary adsorption data. The adsorption
of reaction species occurs in the order o-nitrophenol > o-aminophenol ≫ water and it is strongly
influenced by the solvent used.