Cu(II) impregnated clay-derived HS zeolite: Synthesis, characterization and catalytic activity on catalytic wet peroxide oxidation (CWPO) of phenol

Abstract

The majority of phenol-containing liquid industrial wastes are discharged into natural waters. As a result, several investigations, such as catalytic wet peroxide oxidation (CWPO), have been conducted to remediate these effluents. Copper-supported heterogeneous catalysts were prepared by an impregnation technique and tested in CWPO of phenol. Both the raw pyrophyllite clay and its zeolite form were used as supports. The samples were characterized by BET specific surface area analysis, X-ray diffraction, X-ray fluorescence, and X-ray photoelectron spectra. The effect of temperature (25–70 °C), the concentration of hydrogen peroxide (2–10 mmol·L−1), and the amount of catalyst (0.5–3 g·L−1) were selected for optimization of the catalytic system H2O2-2.5% Cu/ZP using the response surface methodology based on central composite design. The catalyst (2.5% Cu/ZP), with support of synthesized hydroxysodalite zeolite form, showed the best catalytic activity in comparison to that based on raw pyrophyllite support (2.5% Cu/RP). The maximized degradation was 100% after 4 h at optimum conditions (T = 50 °C, [H2O2] = 6.39 mmol·L−1, catalyst amount = 1.82 g·L−1) with 87.73% of mineralization.