The hydrogenation of 4-nitroacetophenone (4-NAP) and 4-aminoacetophenone (4-AAP) was examined over rhodium/silica catalysts. The reactions were carried out using isopropanol as the solvent under a range of temperatures (303-333 K) and pressures (1-5 barg). An activation energy of 50 +/- 14 mol(-1) was determined for 4-NAP hydrogenation and 48 +/- 2 kJ mol(-1) for 4-AAP hydrogenation. Orders of reaction were obtained for 4-NAP (zero order) and hydrogen (first order) and a kinetic isotope effect of 3.0 was observed for 4-NAP hydrogenation and similar to 1.4 for 4-AAP hydrogenation when deuterium was used. Under specific conditions high yields (similar to 94%) to 4-aminoacetophenone and 1-(4-aminophenyl) ethanol could be obtained from 4-NAP hydrogenation. An antipathetic metal crystallite particle size effect was observed for both reactants. (C) 2014 Elsevier B.V. All rights reserved.