Kinetics of wet peroxide oxidation of phenol with a gold/activated carbon catalyst

• Au/AC is an active and efficient catalyst for CWPO of phenol.
• The Au/AC catalyst provided a good performance within a wide pH range (from acidic to neutral).
• The activity of Au/AC can be recovered by a thermal treatment at 200 °C in air.
• A kinetic model including catalyst deactivation has been developed.

Gold nanoparticles supported on activated carbon (Au/AC) have been tested in catalytic wet peroxide oxidation using phenol as target pollutant. In the current work, the effect of several operating conditions, including initial pH (3.5–10.5), catalyst load (0–6 g/L), initial phenol concentration (0.1–5 g/L), hydrogen peroxide dose (4–100% of the theoretical stoichiometric amount) and reaction temperature (50–80 °C) has been investigated. The results show that the Au/AC catalyst would be useful at relatively high pollutant to catalyst ratios (at least 0.4 w/w) and it can work efficiently within a wide range of pH (3.5–7.5). The catalyst suffers rapid deactivation but its activity can be completely restored by an oxidative thermal treatment at low temperature (200 °C). A kinetic model is presented, capable of describing the experimental results. This model is based on a rate equation of order one for hydrogen peroxide consumption and two for phenol oxidation and includes the catalyst deactivation and its temperature dependence.

Figure optionsDownload as PowerPoint slide