Search query: oxidation of organic compounds

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abstract: Abstract Advanced oxidation processes (AOPs) introduce a hopeful technology for the removal of water polluted with hard degradable organic compounds. Today, one of the main effective AOP technologies to degrade these hazardous organics is via the photocatalytic process. The present review focuses on the recent progress in the fixed bed and immobilized nanophotocatalysts and also their applications for resolving the environmental concerns. Various organics elimination using a variety of photocatalysts and innovative reactors are discussed. This critical review summarizes the recent progress in the synthesis and modification (physical and chemical) of semiconductors. Furthermore, different ways of photocatalysts immobilization are explained in details. By considering different dangerous chemicals present in wastewater and different industries, catalytic methods used by researchers to degrade these organic compounds are reviewed. In addition, the degradation pathway of some organics through the catalytic operation is described.
author_names: Abdollah Gholami Akerdi

Seyed Hajir Bahrami
title: Application of heterogeneous nano semiconductors for photocatalytic advanced oxidation of organic compounds: A review
venue: Journal of Environmental Chemical Engineering
year: 2019

abstract: Peroxymonosulfate (HSO5 and PMS) is an optional bulk oxidant in advanced oxidation processes (AOPs) for treating wastewaters. Normally, PMS is activated by the input of energy or reducing agent to generate sulfate or hydroxyl radicals or both. This study shows that PMS without explicit activation undergoes direct reaction with a variety of compounds, including antibiotics, pharmaceuticals, phenolics, and commonly used singlet oxygen (1O2) traps and quenchers, specifically furfuryl alcohol (FFA) azide, and histidine. Reaction time frames varied from minutes to a few hours at pH 9. With the use of a test compound with intermediate reactivity (FFA) electron paramagnetic resonance (EPR) and scavenging experiments ruled out sulfate and hydroxyl radicals. Although 1O2 was detected by EPR and is produced stoichiometrically through PMS self decomposition, 1O2 plays only a minor role due to its efficient quenching by water, as confirmed by experiments manipulating the 1O2 formation rate (addition of H2O2) or lifetime (deuterium solvent isotope effect) Direct reactions with PMS are highly pH and ionic strength sensitive and can be accelerated by (bi)carbonate, borate, and pyrophosphate (although not phosphate) via non radical pathways. The findings indicate that direct reaction with PMS may steer degradation pathways and must be considered in AOPs and other applications. They also signal caution to researchers when choosing buffers as well as 1O2 traps and quenchers.
author_names: Yi Yang

Gourab Banerjee

Gary W Brudvig

Jae-Hong Kim

Joseph J Pignatello
title: Oxidation of Organic Compounds in Water by Unactivated Peroxymonosulfate.
venue: Environmental science technology
year: 2018

abstract: Schiff bases and their complexes are good candidates as versatile compounds which are synthesized by the condensation of a primary amino compound with either aldehydes or ketones for a variety of industrial applications. They can act as catalysts in the catalytic oxidation of organic compounds. Recent researches in oxidation catalysis have focused on how to employ the metal catalyzed oxidation of organic substrates. This review summarizes the current developments of the last few decades for the oxidations of organic compounds that proceed through Schiff base complexes. The chemical syntheses of Schiff bases and their complexes are outlined.
author_names: Wail Al Zoubi

Young Gun Ko
title: Schiff base complexes and their versatile applications as catalysts in oxidation of organic compounds: part I
year: 2017

abstract: Abstract Carbon nanotubes (CNTs) have been found to activate persulfates (i.e. peroxymonosulfate and peroxydisulfate) into reactive species that are capable of oxidizing organic compounds in water. In the presence of single or multi walled CNTs, persulfates effectively degraded phenolic compounds and certain pharmaceuticals. Phenyl derivatives substituted with electron withdrawing groups, such as benzoic acid and nitrobenzene, were resistant to degradation by the CNT/persulfate system. Based on observations regarding persulfate decomposition and linear sweep voltammetry using a CNT electrode, it has been suggested that persulfates bind onto the surface of CNTs, forming reactive complexes that are immediately decomposed upon reaction with organic compounds. Electron paramagnetic resonance spectroscopy with spin trapping indicates that these reactive species are distinct from sulfate radical anions or hydroxyl radicals. The CNT activated persulfate system shows promise as a novel treatment technology for the selective oxidation of organic contaminants in water.
author_names: Hongshin Lee

Hye Jin Lee

Joonseon Jeong

Jaesang Lee

Noh-Back Park

Changha Lee
title: Activation of persulfates by carbon nanotubes: Oxidation of organic compounds by nonradical mechanism
year: 2015

abstract: Significance Highly oxygenated molecules are involved in autooxidation reactions leading to the formation of secondary organic aerosols (SOAs) they are also critical intermediates in autooxidation processes for liquid hydrogen degradation and the ignition of fuels in advanced combustion systems. However, these reactions are still poorly understood. In this study, we unveil a generalized reaction mechanism involving the autooxidation of peroxy radicals with at least three stages of sequential O2 addition. We elucidate important underlying kinetics and structural characteristics of autooxidation processes used for developing new technologies including those aimed at reducing climatically active SOAs and pollutants from fuel combustion. We show that advances can be made by bridging experimental and theoretical methods used by atmospheric and combustion scientists. Decades of research on the autooxidation of organic compounds have provided fundamental and practical insights into these processes; however, the structure of many key autooxidation intermediates and the reactions leading to their formation still remain unclear. This work provides additional experimental evidence that highly oxygenated intermediates with one or more hydroperoxy groups are prevalent in the autooxidation of various oxygenated (e.g. alcohol, aldehyde, keto compounds, ether, and ester) and nonoxygenated (e.g. normal alkane, branched alkane, and cycloalkane) organic compounds. These findings improve our understanding of autooxidation reaction mechanisms that are routinely used to predict fuel ignition and oxidative stability of liquid hydrocarbons, while also providing insights relevant to the formation mechanisms of tropospheric aerosol building blocks. The direct observation of highly oxygenated intermediates for the autooxidation of alkanes at 500 600 K builds upon prior observations made in atmospheric conditions for the autooxidation of terpenes and other unsaturated hydrocarbons; it shows that highly oxygenated intermediates are stable at conditions above room temperature. These results further reveal that highly oxygenated intermediates are not only accessible by chemical activation but also by thermal activation. Theoretical calculations on H atom migration reactions are presented to rationalize the relationship between the organic compound's molecular structure (n alkane, branched alkane, and cycloalkane) and its propensity to produce highly oxygenated intermediates via extensive autooxidation of hydroperoxyalkylperoxy radicals. Finally, detailed chemical kinetic simulations demonstrate the influence of these additional reaction pathways on the ignition of practical fuels.
author_names: Zhandong Wang

Denisia M Popolan-Vaida

Bingjie Chen

Kai Moshammer

Samah Y Mohamed

Heng Wang

Salim Sioud

Misjudeen A Raji

Katharina Kohse-Hoinghaus

Nils Hansen

Philippe Dagaut

Stephen R Leone

S Mani Sarathy
title: Unraveling the structure and chemical mechanisms of highly oxygenated intermediates in oxidation of organic compounds
venue: Proceedings of the National Academy of Sciences
year: 2017

abstract: Abstract This review presents a critical assessment of the kinetics and mechanisms of the oxidation of organic compounds, X (organosulfur compounds, amines, phenols, alcohols, hydrocarbons, ascorbate, and pharmaceuticals) by ferrate(VI) (Fe VI O 4 2 and ferrate(V) (Fe V O 4 3 The rate constants k app M 1 s 1 of reactions of these compounds with ferrate(VI) and ferrate(V) usually decrease with increase in pH in alkaline media and the species specific rate constants were evaluated from pH dependent kinetics. The rate constants for the reactions of HFe VI O 4 and HFe V O 4 2 with X were correlated with 1 e and 2 e reduction potentials in order to understand the mechanisms of the reactions. Ferrate(V) generally oxidizes compounds by a 2 e transfer step. The reactions of ferrate(VI) with compounds may be characterized most commonly by (i) a 1 e transfer step from Fe(VI) to Fe(V) followed by a 2 e transfer to Fe(III) as the reduced product (Fe VI Fe V Fe III and (ii) 2 e transfer steps (Fe VI Fe IV Fe II Oxygen atom transfer to the compounds may occur through involvement of either ferrate(VI) or ferrate(V) in the oxidations carried out by ferrate(VI) Hammett type relationships of reactions provided additional information on intermediates involved in oxidation processes and proposed mechanisms are consistent with the oxidized products of the reactions. Oxidation of biological species by ferrate(VI) is also briefly presented.
author_names: Virender Kumar Sharma
title: Ferrate(VI) and ferrate(V) oxidation of organic compounds: Kinetics and mechanism
year: 2013

abstract: Abstract The development of new metal complex catalysts and efficient protocols for the mild and selective oxidation of alkanes, arenes, olefins, alcohols, and other organic substrates is a challenging topic in areas of homogeneous catalysis, coordination, and organic chemistry. In these oxidation reactions, the activity of many metal complex catalysts is dramatically improved upon addition of certain co catalysts or promoters, which can also act as ligands in simple catalytic systems generated in situ. Given the fact that 2 pyrazinecarboxylic acid (Hpca) and analogous heteroaromatic acids such as 2,3 pyrazinedicarboxylic (H 2 pdca) picolinic (Hpic) and dipicolinic (H 2 dipic) acids are remarkably efficient and versatile co catalysts in a high diversity of oxidation systems, the present review summarizes the state of the art knowledge in this field. In particular, this contribution focuses on the use of Hpca as the most active co catalyst and describes its coordination chemistry with regard to the oxidative transformations of various organic substrates, providing an overview of isolated vanadium, iron, and some other transition metal complexes derived from Hpca. The review also summarizes the applications of Hpca assisted and related systems in the oxidation of various organic substrates by different oxidants, and highlights the main selectivity, kinetic, and mechanistic features of these oxidative transformations. The paper covers the application of catalytic systems wherein Hpca, H 2 pdca, Hpic, and H 2 dipic are used either as co catalysts (additives) or as ligands within a metal complex catalyst. A special emphasis has been made on the oxidation of alkanes as very inert substrates, and the use of simple and highly efficient [VO 3 /Hpca/H 2 O 2 system. The multifaceted roles of Hpca and analogous co catalysts have been identified and the analysis of main mechanistic pathways and possible intermediates has been performed.
author_names: Alexander M Kirillov

Georgiy B Shul'pin
title: Pyrazinecarboxylic acid and analogs: Highly efficient co catalysts in the metal complex catalyzed oxidation of organic compounds
year: 2013

abstract: The gram negative metal reducing microorganism, previously known as strain GS 15, was further characterized. This strict anaerobe oxidizes several short chain fatty acids, alcohols, and monoaromatic compounds with Fe(III) as the sole electron acceptor. Furthermore, acetate is also oxidized with the reduction of Mn (IV) U (VI) and nitrate. In whole cell suspensions, the c type cytochrome(s) of this organism was oxidized by physiological electron acceptors and also by gold, silver, mercury, and chromate. Menaquinone was recovered in concentrations comparable to those previously found in gram negative sulfate reducers. Profiles of the phospholipid ester linked fatty acids indicated that both the anaerobic desaturase and the branched pathways for fatty acid biosynthesis were operative. The organism contained three lipopolysaccharide hydroxy fatty acids which have not been previously reported in microorganisms, but have been observed in anaerobic freshwater sediments. The 16S rRNA sequence indicated that this organism belongs in the delta proteobacteria. Its closest known relative is Desulfuromonas acetoxidans. The name Geobacter metallireducens is proposed.
author_names: Derek R Lovley

Stephen J Giovannoni

David C White

James E Champine

Elizabeth J P Phillips

Yuri A Gorby

Steve Goodwin
title: Geobacter metallireducens gen. nov. sp. nov. a microorganism capable of coupling the complete oxidation of organic compounds to the reduction of iron and other metals
venue: Archives of Microbiology
year: 2004

abstract: It is well known that urbanization and industrialization have resulted in the rapidly increasing emissions of volatile organic compounds (VOCs) which are a major contributor to the formation of secondary pollutants (e.g. tropospheric ozone, PAN (peroxyacetyl nitrate) and secondary organic aerosols) and photochemical smog. The emission of these pollutants has led to a large decline in air quality in numerous regions around the world, which has ultimately led to concerns regarding their impact on human health and general well being. Catalytic oxidation is regarded as one of the most promising strategies for VOC removal from industrial waste streams. This Review systematically documents the progresses and developments made in the understanding and design of heterogeneous catalysts for VOC oxidation over the past two decades. It addresses in detail how catalytic performance is often drastically affected by the pollutant sources and reaction conditions. It also highlights the primary routes for catalyst deactivation and discusses protocols for their subsequent reactivation. Kinetic models and proposed oxidation mechanisms for representative VOCs are also provided. Typical catalytic reactors and oxidizers for industrial VOC destruction are further discussed. We believe that this Review will provide a great foundation and reference point for future design and development in this field.
author_names: Chi He

Jie Cheng

Xin Zhang

Mark Douthwaite

Samuel Pattisson

Zhengping Hao
title: Recent Advances in the Catalytic Oxidation of Volatile Organic Compounds: A Review Based on Pollutant Sorts and Sources.
venue: Chemical reviews
year: 2019

abstract: Summary The oxidation of a range of organic compounds at a nickel anode in aqueous alkaline solution has been studied and the conversion of primary alcohols, secondary alcohols and primary amines to carboxylic acids, ketones and nitriles respectively have been shown to be efficient processes. most of these organic compounds oxidise at the same potential, the potential at which the surface of the nickel anode itself becomes oxidised. The kinetics for these anodic oxidations have been studied and a mechanism has been proposed to explain the behaviour observed.
author_names: Martin L Fleischmann

Karl A Korinek

Derek Pletcher
title: The oxidation of organic compounds at a nickel anode in alkaline solution
year: 1971