Selective hydrogenation of phenol to cyclohexanone in water over Pd catalysts supported on Amberlyst-45

A series of Pd catalysts were prepared on different supports (Fe 2 O 3 , SiO 2 , ZnO, MgO, Al 2 O 3 , carbon, and Amberlyst-45) and used in the selective hydrogenation of phenol to cyclohexanone in water. The Amberlyst-45 supported Pd catalyst (Pd/A-45) was highly active and selective under mild conditions (40–100 °C, 0.2–1 MPa), giving a selectivity of cyclohexanone higher than 89% even at complete conversion of phenol. Experiments with different Pd loadings (or different particle sizes) confirmed that the formation of cyclohexanone was a structure sensitive reaction, and Pd particles of 12–14 nm on Amberlyst-45 gave better selectivity and stability. Ion-exchange resin Amberlyst-45 supported Pd nanoparticles was highly active and selective for the selective hydrogenation of phenol to cyclohexanone in water under mild conditions (40–100 °C, 0.2–1 MPa).