Catalytic Evaluation of CuO/[Si]MCM‐41 in Fenton‐like Reactions

Abstract

CuO/[Si]MCM‐41 catalysts with various Si/Cu molar ratios were prepared and characterized by X‐ray diffraction, nitrogen physisorption, temperature‐programmed reduction by H2, and UV‐vis and Raman spectroscopy. The effects of copper loading and pH on their activity in the decolorization of methyl orange were studied in a heterogeneous Fenton‐like process. With decreasing Si/Cu ratio, dye decolorization increased from 18 to 75 % at pH 3. CuO/[Si]MCM‐41 catalysts showed 75, 50, and 40 % conversion of methyl orange at pH 3, 5, and 7, respectively. This is a significant improvement to Fenton‐like reactions involving copper, and thus CuO/[Si]MCM‐41 catalysts are quite promising for pollutant degradation.

Kinetic and Mechanistic Study of Rhodamine B Degradation by H2O2 and Cu/Al2O3/g-C3N4 Composite

“…However, Cu + ions are prone to disproportionation in acidic aqueous solution and can be easily oxidized by dissolved O 2 , thereby limiting the application in the aqueous environment [23]. One common strategy for the preparation of copper-based catalysts is the immobilization of copper species on support materials, for example, the immobilization of Cu + /Cu 2+ , copper oxide, or the copper-organic complex [24] on various matrixes like metal oxides [25][26][27], molecular sieve [28,29], and graphitic carbon nitride (g-C 3 N 4 ) [30,31].…”

Fe2O3/MCM‐41 as catalysts for methyl orange degradation by Fenton‐like reactions

“…Some advantages of heterogeneous Fenton processes are high mineralization degree of organic compounds at room temperature and easy separation of heterogeneous catalysts from treated wastewater. Consequently, the use of solid catalysts in Fenton or Fenton‐like reactions has become scientifically relevant 16‐18 . Catalysts employed in heterogeneous systems are usually pure iron oxides or iron oxides impregnated onto different supports, such as zeolites, 19 clay, 19 silica, 18‐21 alumina, 22 niobium, 23 and various types of carbonaceous materials 24 .…”

“…These characteristics make it ideal for adsorption and catalytic applications 25,29,30 . In a previous work, 16 MCM‐41 was used to support CuO in which CuO/[Si]MCM‐41 catalysts were evaluated in a heterogeneous Fenton‐like process and presented good performance at decolorizing MO in a pH range of 3.0–7.0. Copper was used as active phase since it also decomposes H 2 O 2 via a Fenton‐like reaction to produce • OH radicals.…”

“…Copper was used as active phase since it also decomposes H 2 O 2 via a Fenton‐like reaction to produce • OH radicals. However, a slightly higher efficiency can be achieved by using iron in Fenton reactions if compared to those involving copper as catalyst 1,13,16 . Iron containing MCM‐41 (Fe‐MCM‐41) has diverse redox properties and proves useful to treat various organic pollutants in aqueous media 29,31‐36 .…”

“…Catalysts having different SiO 2 /Fe 2 O 3 molar ratios have been synthesized and thoroughly characterized by N 2 adsorption–desorption, X‐ray fluorescence (XRF), X‐ray diffraction (XRD), UV–vis spectroscopy and H 2 temperature programmed reduction (H 2 ‐TPR). MO has been selected to represent the target pollutant treated via heterogeneous Fenton reaction, which is susceptible to degradation in Fenton processes 2,16,40 . In addition, a detailed investigation on chemical oxygen demand (COD) removal aimed to examine the extent of mineralization and catalyst reusability in consecutive cycles has been conducted.…”