Fast-growing field of magnetically recyclable nanocatalysts.

Perovskite oxides with formula ABO3 or A2BO4 are a very important class of functional materials that exhibit a range of stoichiometries and crystal structures. Because of the structural features, they could accommodate around 90% of the metallic natural elements of the Periodic Table that stand solely or partially at the A and/or B positions without destroying the matrix structure, offering a way of correlating solid state chemistry to catalytic properties. Moreover, their high thermal and hydrothermal stability enable them suitable catalytic materials either for gas or solid reactions carried out at high temperatures, or liquid reactions carried out at low temperatures. In this review, we addressed the preparation, characterization, and application of perovskite oxides in heterogeneous catalysis. Preparation is an important issue in catalysis by which materials with desired textural structure and physicochemical property could be achieved; characterization is the way to explore and understand the textura...

Perovskite Oxides: Preparation, Characterizations, and Applications in Heterogeneous Catalysis

Heterogeneous Fenton reactions have gained widespread attention in removing recalcitrant organic contaminants as the reaction between solid Fenton catalysts and H2O2 can generate highly reactive hydroxyl radicals (HO[rad]). However, several drawbacks, such as the low-speed generation of Fe(II), high consumption of H2O2, and acidic reaction conditions (generally at ˜ pH 3), are always the core issues that hamper the large-scale application of heterogeneous Fenton reactions in environmental remediation. Thus, a large number of studies have been devoted to tackling these drawbacks, and this paper intends to comprehensively review the developed strategies for enhancing heterogeneous Fenton reactivity, mainly over the last decade. Based on a comprehensive survey of previous studies, we categorize these strategies according to their reaction mechanisms. For example, introducing additional electrons (e.g., from external electric fields, electron-rich materials, semiconductors, plasmonic materials, or doped metals) to heterogeneous Fenton catalysts can accelerate the generation of Fe(II); the in situ generation of H2O2 can be achieved by combining ultrasound, electricity, semiconductors, and iron-based catalysts in the system; and controlling the specific morphologies and exposed facets of heterogeneous Fenton catalysts can greatly promote the decomposition of H2O2. In addition, we briefly introduce some recent novel heterogeneous Fenton-like reactions that are of particular interest, including constructing dual reaction centers (i.e., the electron-poor center and the electron-rich center) and synthesizing single-atom catalysis-based heterogeneous Fenton-like catalysts. Moreover, this review article analyzes and compares the merits of each strategy for enhancing heterogeneous Fenton/Fenton-like reactions. We believe this review can motivate the construction of novel and efficient heterogeneous Fenton/Fenton-like systems and help readers choose proper Fenton/Fenton-like reaction systems for industrial applications.

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Strategies for Enhancing the Heterogeneous Fenton Catalytic Reactivity: A review

This study presents a critical review on the application of magnetite-based catalysts to industrial wastewater decontamination by heterogeneous Fenton oxidation. The use of magnetic materials in this field started only around 2008 and continues growing increasingly year by year. The potential of these materials derives from their higher ability for degradation of recalcitrant pollutants compared to the conventional iron-supported catalysts due to the presence of both Fe(II) and Fe(III) species. In addition, their magnetic properties allow their easy, fast and inexpensive separation from the reaction medium. The magnetic materials applied up to now can be classified in three general groups: magnetic natural minerals, in-situ-produced magnetic materials and ferromagnetic nanoparticles. A survey of the catalysts investigated so far is presented paying attention to their nature and competitive features in terms of activity and durability.

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Preparation of magnetite-based catalysts and their application in heterogeneous Fenton oxidation – A review

Review on the application of modified iron oxides as heterogeneous catalysts in Fenton reactions

Nano-sized magnetic iron oxides as catalysts for heterogeneous Fenton-like reactions—Influence of Fe(II)/Fe(III) ratio on catalytic performance

LaFeO3 and BiFeO3 perovskites as nanocatalysts for contaminant degradation in heterogeneous Fenton-like reactions

Although the uniform initial hydroxylation of methyl tert-butyl ether (MTBE) and other oxygenates during aerobic biodegradation has already been proven by molecular tools, variations in carbon and hydrogen enrichment factors (eC and eH) have still been associated with different reaction mechanisms (McKelvie et al. Environ. Sci. Technol. 2009, 43, 2793–2799). Here, we present new laboratory-derived eC and eH data on the initial degradation mechanisms of MTBE, ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME) by chemical oxidation (permanganate, Fenton reagents), acid hydrolysis, and aerobic bacteria cultures (species of Aquincola, Methylibium, Gordonia, Mycobacterium, Pseudomonas, and Rhodococcus). Plotting of Δδ2H/ Δδ13C data from chemical oxidation and hydrolysis of ethers resulted in slopes (Λ values) of 22 ± 4 and between 6 and 12, respectively. With A. tertiaricarbonis L108, R. zopfii IFP 2005, and Gordonia sp. IFP 2009, eC was low (<|−1|‰) and eH was insignificant. Fractionation obtain...

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Klara Rusevova

Papers

Nano-sized magnetic iron oxides as catalysts for heterogeneous Fenton-like reactions—Influence of Fe(II)/Fe(III) ratio on catalytic performance

LaFeO3 and BiFeO3 perovskites as nanocatalysts for contaminant degradation in heterogeneous Fenton-like reactions

Critical Evaluation of the 2D-CSIA Scheme for Distinguishing Fuel Oxygenate Degradation Reaction Mechanisms

Stabilization of potassium permanganate particles with manganese dioxide.