Supported Cu(II) polymer catalysts for aqueous phenol oxidation

Abstract

Supported Cu(II) polymer catalysts were used for the catalytic oxidation of phenol at 30 °C and atmospheric pressure using air and H 2O 2 as oxidants. Heterogenisation of homogeneous Cu(II) catalysts was achieved by adsorption of Cu(II) salts onto polymeric matrices (poly(4-vinylpyridine), Chitosan). The catalytic active sites were represented by Cu(II) ions and showed to conserve their oxidative activity in heterogeneous catalysis as well as in homogeneous systems. The catalytic deactivation was evaluated by quantifying released Cu(II) ions in solution during oxidation, from where Cu–PVP 25 showed the best leaching levels no more than 5 mg L −1. Results also indicated that Cu–PVP 25 had a catalytic activity (56% of phenol conversion when initial Cu(II) catalytic content was 200 mg L Reaction − 1 ) comparable to that of commercial catalysts (59% of phenol conversion). Finally, the balance between activity and copper leaching was better represented by Cu–PVP 25 due to the heterogeneous catalytic activity had 86% performance in the heterogeneous phase, and the rest on the homogeneous phase, while Cu–PVP 2 had 59% and CuO/γ-Al 2O 3 68%.