Chemoselective Liquid Phase Hydrogenation of 3-Nitrostyrene over Pt Nanoparticles: Synergy with ZnO Support

Hydrogenation of 3-nitrostyrene was performed at T = 348 K and 10 bar over platinum nanopartides supported on several metal oxides. Pt/Al2O3 and Pt/C catalysts exhibited high activity giving 3-ethylaniline as the only product, while Pt/ZnO displayed high selectivity toward target 3-vinylaniline at close to full substrate conversion due to PtZn alloy formation. The catalyst also showed a robust behavior without detectable catalyst deactivation in repeated reaction runs. The most suitable solvent for this reaction was ethanol. Kinetic modeling for nitrostyrene hydrogenation was successfully performed based on the proposed parallel-consecutive reaction network. Application of Pt/ZnO for hydrogenation of various 3-substituted (-CH3, -H, -Cl, -Br, -CHCH2, -COOH, and -NO2) nitroarenes resulted in almost exclusive formation of the corresponding aminocompounds.