Accelerated Catalytic Fenton Reaction with Traces of Iron: An Fe–Pd-Multicatalysis Approach

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• 作者：Anett Georgi ; Miriam Velasco Polo ; Klara Crincoli ; Katrin Mackenzie ; Frank-Dieter Kopinke
• 刊名：Environmental Science & Technology
• 出版年：2016
• 出版时间：June 7, 2016
• 年：2016
• 卷：50
• 期：11
• 页码：5882-5891
• 全文大小：466K
• 年卷期：0
• ISSN：1520-5851

文摘

An accelerated catalytic Fenton (ACF) reaction was developed based upon a multicatalysis approach, facilitating efficient contaminant oxidation at trace levels of dissolved iron. Beside the Fe^II/H₂O₂ catalyst/oxidant pair for production of OH-radicals, the ACF system contains Pd/H₂ as catalyst/reductant pair for fast reduction of Fe^III back to Fe^II which accelerates the Fenton cycle and leads to faster contaminant degradation. By this means, the concentration of the dissolved iron catalyst can be reduced to trace levels (1 mg L^–1) below common discharge limits, thus eliminating the need for iron sludge removal, which is one of the major drawbacks of conventional Fenton processes. ACF provides fast degradation of the model contaminant methyl tert-butyl ether (MTBE, C₀ = 0.17 mM) with a half-life of 11 min with 1 mg L^–1 dissolved iron, 500 mg L^–1 H₂O₂, 5 mg L^–1 Pd (as suspended Pd/Al₂O₃ catalyst) and 0.1 MPa H₂, pH 3. The effects of pH, H₂ partial pressure and H₂O₂ concentration on MTBE degradation rates were studied. Results on kinetic deuterium isotope effect and quenching studies are in conformity with OH-radicals as main oxidant. The heterogeneous Pd/Al₂O₃ catalyst was reused within six cycles without significant loss in activity.