Behavior of Cu–Ce/AC catalyst–sorbent in dry oxidation of phenol

An activated carbon-supported copper and cerium catalyst–sorbent (Cu–Ce/AC) is studied for phenol adsorption from a water phase and catalytic oxidation of the adsorbed phenol under dry conditions. The Cu–Ce/AC has high phenol adsorption capacities and high phenol oxidation activities. The phenol saturation adsorption capacity of the fresh Cu–Ce/AC is about 209 mg/g. With increasing adsorption–oxidation cycles (repeat uses), the phenol adsorption capacity decreases consecutively to a stable value of about 78 mg/g when the oxidation is carried out at 250 °C for 2 h, which is better than that of other types of AC-based materials. The initial oxidation temperature for phenol is about 160 °C, which is 150 °C lower than the ignition temperature of the AC. The main oxidation products are CO2 and H2O with a small amount of desorbed phenol. The decrease in phenol adsorption capacity after the oxidation is caused by the formation of phenol polymeric residues, which block the micro-pore and perhaps cover the active sites.