Oxidation of hazardous compounds by heterogeneous catalysis based on Cu/Al2O3 system in Fenton­type reactions

Abstract

This review examines in detail all components involved in heterogeneous Fenton-type reactions, with special focus on copper species supported on alumina for H2O2 decomposition, their redox chemistry, and their practical advantages over traditional Fenton for the degradation of recalcitrant organic compounds. Several aspects for a deeper comprehension of the properties of γ-Al2O3 as support for catalytic applications are discussed. Iron-free systems stability after calcination and catalyst performance during the oxidation reaction are evaluated to solve the disadvantages of iron-based system. Copper species supported on alumina for H2O2 decomposition in Fenton-like reactions are examined, with special focus on their redox chemistry and practical advantages over traditional Fenton system for recalcitrant compounds degradation. Characterization techniques for the elucidation of the structures, compositions, and chemical properties of both the solids used in heterogeneous catalysis, and the adsorbates and intermediates present on the surfaces of the catalysts during reaction are explained. Global indicators for chemical characterization of wastewaters and measurement of catalytic efficiency are described.