Enhanced heterogeneous wet hydrogen peroxide catalytic oxidation performance of fly ash-derived zeolite by CuO incorporation

Abstract

Copper oxide incorporated fly ash-derived zeolite X (CuO/FAZ-X) was synthesized from solid waste coal fly ash by ion exchange with Cu2+ followed by calcination process. The synthesized materials were characterized by XRF, FTIR, SEM, EDX, and BET methods. In the application of the catalysts for wet peroxide oxidative decolorization of the model dye MB (Methylene Blue), the effects of major parameters, such as CuO loading, initial H2O2 concentration, initial dye concentration, catalyst dosage, and pH, were investigated to assess the activity of the catalysts. In comparison with the activity of either fly ash-derived zeolite X (FAZ-X) or CuO, the combined catalyst (CuO/FAZ-X) showed an enhanced wet catalytic activity. Under the optimal condition (catalyst dose 250 mg/L, 100 ppm dye, pH = 6.8, 1 ml H2O2, and room temperature or 30ffiC), the decolorization of MB was about 100% in 120 min by CuO/FAZ-X and only 31% and 44% by FAZ-X and CuO, respectively. Based on the decolorized products identified by HPLC-(-ESI)-TOFMS, the decolorization pathway of MB was proposed. Consequently, incorporation of CuO remarkably improved the catalytic activity of FAZ-X, such that CuO/FAZ-X emerged as a novel, reusable heterogeneous Fenton-like catalyst for oxidative decolorization of model dye MB. Thus, the present work demonstrates a simple and facile route for the conversion of waste coal fly ash into a valuable catalyst.