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144-62-7Relevant articles and documents
Site-Selective Growth of AgPd Nanodendrite-Modified Au Nanoprisms: High Electrocatalytic Performance for CO2 Reduction
Shan, Changsheng,Martin, Erin T.,Peters, Dennis G.,Zaleski, Jeffrey M.
, p. 6030 - 6043 (2017)
Environmental impacts of continued CO2 production have led to an increased need for new methods of CO2 removal and energy development. Nanomaterials are of special interest for these applications, because of their unique chemical and physical properties that allow for highly active surfaces. Here, we successfully synthesize AgPd nanodendrite-modified Au nanoprisms in various shapes (nanoprisms, hexagonal nanoplates, and octahedral nanoparticles) by selective metal deposition. This strategy involves coupling galvanic replacement between Ag layers in Au@Ag core-shell nanoprisms and H2PdCl4 with a coreduction process of silver and palladium ions. Synthesis of AgPd nanodendrite-tipped (4.14-11.47 wt % Pd) and -edged (25.25-31.01 wt % Pd) Au nanoparticles can be controlled simply by tuning the concentration of H2PdCl4. More importantly, these multicomponent AgPd nanodendrite-modified Au nanoparticles show exceptional electrocatalytic performance for CO2 reduction. AgPd nanodendrite-edged Au nanoprisms show more favorable potentials (-0.18 V vs RHE) than previously reported nanocatalysts for the reduction of CO2 to formate, and exhibit higher faradaic efficiencies (49%) than Au, Au@Ag, and AgPd nanodendrite-tipped Au nanoprisms in aqueous electrolytes. Moreover, AgPd nanodendrite-modified Au nanoprisms show much higher selectivity and faradaic efficiency for CO2 reduction to CO (85-87%) than Au and Au@Ag nanoprisms (43-64%) in organic electrolytes. The high performance of these particles for CO2 reduction is attributed to the unique structure of AgPd nanodendrite-modified Au nanoprisms and the synergistic effect of Ag having an affinity for CO2, efficient binding of hydrogen at Pd, and Au as a stable, conductive support. In addition, AgPd nanodendrite-edged Au nanoprisms show highly stable catalytic activity during long-term electrolyses (up to 12 h) and repetitive use. These exciting results indicate that AgPd nanodendrite-modified Au nanoparticles are promising for application in CO2 conversion into useful fuels.
The ozonization of model lignin compounds in aqueous solutions catalyzed by Mn(II) ions
Mitrofanova,Khudoshin,Lunin
, p. 1141 - 1146 (2010)
The influence of Mn(II) ions on the rate of the reaction between ozone and model lignin compounds, guaiacol and veratrole, was studied. The catalyst did not influence the rate of the destruction of the aromatic ring and intermediate ozonolysis products, compounds with conjugated double bonds, in acid media but substantially increased the rate of oxidation of saturated carboxylic acids, ketoacids, and aldehydes. Ozone consumption then increased from 2 to 5 moles per mole of the transformed substrate. A mechanism of the catalytic action of Mn(II) in reactions between ozone and the compounds studied was suggested.
Electrochemical reduction of CO2 in a mixed supercritical fluid
Abbott, Andrew P.,Eardley, Christopher A.
, p. 775 - 779 (2000)
The electroreduction of CO2 in the liquid and supercritical states was studied on both Pt and Pb electrode surfaces using a mixture of 1,1,1,2-tetrafluoroethane (HFC 134a) and CO2 solvent. A decrease in the reduction potential on both electrode materials was observed in the supercritical state compared with the liquid state. Platinum was far better than lead as a cathode material on which to reduce CO2 in supercritical CO2/HFC 134a mixture by both voltametric and bulk electrolysis experiments. The use of the supercritical mixture, rather than an aprotic liquid as electrochemical solvent, significantly improved the faradaic efficiency of oxalate formation at a Pt electrode, which can be due to the high CO2 concentration at the electrode surface in the mixture.
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Vaughan,Yoshimine
, p. 528,531 (1957)
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Kudernatsch
, p. 613 (1897)
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Herzig
, p. 738 (1898)
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Kearns, M. L.,Heiser, L.,Nieuwland, J. A.
, p. 795 (1923)
Improving the efficiency of Fenton reactions and their application in the degradation of benzimidazole in wastewater
Liu, Qinyao,Qian, Kun,Qi, Jinxu,Li, Chenru,Yao, Chen,Song, Wei,Wang, Yihong
, p. 9741 - 9748 (2018)
Reducing the quantity of sludge produced in Fenton reactions can be partly achieved by improving their efficiency. This paper firstly studies the effect of uniform deceleration feeding (ferrous iron and hydrogen peroxide) on the efficiency of a Fenton reaction by measuring the yield of hydroxyl radicals (OH) and chemical oxygen demand (COD) removal rate. The dynamic behavior of OH was also investigated. The results indicated that uniform deceleration feeding was the best feeding method compared with one-time feeding and uniform feeding methods when the same amount of Fenton reagents and the same reaction times were used. Besides, it was found the COD removal rate reached 79.3% when this method was applied to degrade 2-(a-hydroxyethyl)benzimidazole (HEBZ); this COD removal rate is larger than those when the other two modes were used (they reached 60.7% and 72.1%, respectively). The degradation pathway of HEBZ was determined using PL, UV-vis, FTIR, HPLC and GC-MS. Ultimately, HEBZ was decomposed into three small molecules (2-hydroxypropylamine, oxalic acid, and 2-hydroxypropamide). This research is of great significance for the application of Fenton reactions in wastewater treatment.
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Radcliffe,Short
, p. 1200,1202 (1938)
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Frankel et al.
, p. 1119 (1957)
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Ozonation of azo dye Acid Black 1 under the suppression effect by chloride ion
Paprocki, Alexandre,Dos Santos, Heldiane S.,Hammerschitt, Marta E.,Pires, Marc?al,Azevedo, Carla M. N.
, p. 452 - 460 (2010)
The aim of this study is to determine the kinetics of the Acid Black 1 dye by oxidizing action of ozone and to evaluate the influence of chloride ion contamination on the dye degradation. Pseudo-first order kinetics was observed for both decolorization (620 nm) and aromatic structure (321 nm) degradations. A complete color removal was verified in 25 min ([dye]0 = 1.8 × 10 -5 mol L-1), while aromatic structures degraded at slower rates. The presence of chloride ion, the principal impurity of the solid dye reagents, influences significantly the ozonation rate (-42percent), even at low chloride concentration (5.6 × 10-4 mol L-1). The most probable mechanism for the chloride suppression effect involves a direct reaction between O3 and Cl- generating HOCl, among other by-products. In despite of that, ozonation could be a competitive degradation process for this dye.
Mereshkowski
, (1915)
Real-Time FTIR Spectroscopy as a Quantitative Kinetic Probe of Competing Electrooxidation Pathways for Small Organic Molecules
Leung, Lam-Wing H.,Weaver, Michael J.
, p. 4019 - 4022 (1988)
The application of real-time FTIR spectroscopy to probe quantitative kinetics and mechanisms of competing electrochemical patways on a voltammetric time scale is illustrated for the electrooxidation of ethanol, ethylene glycol, and glycolaldehyde in 0.1 M HClO4 at platinum.A simple procedure is outlined whereby the required ratio of molar absorptivities in the thin-layer cavity and bulk solution εeff/εb, can be evaluated.This approach enables the proportion of CO2 and partial oxidation products formed during voltammetric sweeps to be determined reliably and the role of adsorbed CO and other chemisorbed fragments in the electrocatalytic mechanisms to be evaluated.
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Adams et al.
, p. 2439 (1941)
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Evans et al.
, p. 2267 (1928)
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Rao
, p. 1162,1184 (1930)
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Clemo,Raper
, p. 644 (1933)
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Degradation of atrazine by Fenton and modified Fenton reactions
MacKul'Ak, Tomas,Prousek, Josef,Svorc, L'Ubomir
, p. 561 - 567 (2011)
For 50 years, farmers around the world have relied on the herbicide atrazine-one of the triazine family of herbicides-to fight weeds in corn, grain sorghum, sugar cane, and other crops. Although prohibited in the European Union because of widespread contamination of waterways and drinking water supplies, it is still one of the most widely used herbicides in the world. Atrazine and some of its degradation products are among the most commonly found xenobiotics in groundwater and soils in the world. It is also an endocrine disruptor that causes abnormal reproductive development and immune suppression in wildlife. The purpose of this study was to identify the degradation products of atrazine. Fenton reaction treatment, a hydroxyl radical oxidation process recently developed for the degradation of aqueous pesticide waste, was applied to the degradation of atrazine. Classical and modified Fenton reactions have been used as Advanced Oxidation Process treatment methods. A HPLC method was developed and optimized for the identification of resulting degradation products. In general, very good atrazine degradation efficiencies were achieved by both of the methods used. The degradation products, such as oxalic acid, urea, formic acid, acetic acid, and acetone, were identified by HPLC with a photodiode array detector.
Oxidation of glyoxal initiated by ?OH in oxygenated aqueous solution
Buxton, George V.,Malone, Treena N.,Salmon, G. Arthur
, p. 2889 - 2891 (1997)
The kinetics and mechanism of the oxidation of glyoxal, which is a constituent of cloud water, initiated by ?OH in oxygenated solution have been investigated using pulse radiolysis with optical and conductivity detection of the transient species, and steady-state radiolysis with spectrophotometric and ion chromatographic analysis of the permanent products. The data obtained are consistent with glyoxal being present in the form of the dihydrate [CH(OH)2]2 which is oxidised to glyoxylic acid (pK2 = 3.4) and hydrogen peroxide via a peroxyl radical ?O2C(OH)2CH(OH)2 that splits off HO2? in a non-rate determining step. The following rate constants have been determined: k{?OH + [CH(OH)2]2} = (1.10 + 0.04) × 109 dm3 mol-1 s-1 and k[?C(OH)2CH(OH)2 + O2] = (1.38 ± 0.11) × 109 dm3 mol-1 s-1. It is concluded that oxidation of glyoxal by ?OH in cloud water can proceed by a chain reaction involving H2O2.
Engaging thieno[2,3-b]indole-2,3-dione for the efficient synthesis of spiro[indoline-3,4′-thiopyrano[2,3-b]indole] by reaction with N-substituted isatilidenes
Thomas, Noble V.,Sathi, Vidya,Deepthi, Ani,Sudheendran Leena, Sruthi,Chopra, Sidharth
, p. 48 - 55 (2021)
A simple and efficient method, proceeding through a new mechanistic pathway, for the synthesis of spiro[indoline-3,4-thiopyrano[2.3-b]indole derivatives have been developed by exploiting the reaction of thieno[2,3-b]indole-2,3-dione with N-substituted isatilidenes. The compounds synthesized have been screened for antibacterial activity. The generality of the reaction and mechanistic rationale are presented.
Catalytic ozonation of 4-chlorophenol and 4-phenolsulfonic acid by CeO2 films
Guzmán, Iveete C.,Rodríguez, Julia L.,Poznyak,Chairez, Isaac,Hernández, Isaías,Hernández, Roberto T.
, (2020)
Ceria films (CeO2(f)) were deposited on glass substrate by a spray pyrolysis method. The catalytic oxidation performance of CeO2(f) was evaluated in the removal of 4-chlorophenol (4-CPh) and 4-phenolsulfonic acid (4-SPh). The catalytic oxidation reactions were carried out in water with ozone as an oxidant agent. Conventional and catalytic ozonation achieved complete removal of both compounds. Furthermore, TOC results showed higher catalytic activity with six CeO2(f) films in comparison with conventional ozonation after 120 min for the oxidation of both 4-CPh and 4-SPh. After five consecutive reuses of CeO2(f), the similar TOC removal for 4-CPh demonstrated the ceria films stability.
Identification of 3,4-dihydroxy-2-oxo-butanal (L-threosone) as an intermediate compound in oxidative degradation of dehydro-L-ascorbic acid and 2,3-diketo-L-gulonic acid in a deuterium oxide phosphate buffer.
Nishikawa,Toyoshima,Kurata
, p. 1707 - 1712 (2001)
Dehydro-L-ascorbic acid (DAA), an oxidation product of L-ascorbic acid (vitamin C), is unstable in the neutral and basic pH regions. When DAA was incubated in a phosphate buffer with deuterium oxide (pH 7.4), it was degraded to form the main degradation compound, which was identified as 3,4-dihydroxy-2-oxobutanal (L-threosone). This compound was also formed from diketo-L-gulonic acid (DKG) in a phosphate buffer with deuterium oxide. L-threosone had reducing activity, probably due to its enolization, and is likely to have been involved in the formation of the reducing activity that was observed in aqueous DAA and DKG solutions. As a reactive dicarbonyl compound, L-threosone might also take some role in the cross-linking of tissue proteins that are formed in vivo in the Maillard reaction.
VOLUBOLIN, A 4-PHENYL-2H-1-BENZOPYRAN-2ONE FROM DALBERGIA VOLUBILIS
Chawla, H. Mohindra,Mittal, Ram S.
, p. 2625 - 2626 (1983)
From the ether soluble portion of a methanolic extract of young non-green branches of Dalbergia volubilis, sitosterol, 7-hydroxy-4-methyl-2H-1-benzopyran-2-one, dalbergin, p-hydroxy cinnamic acid, biochanin-A and a new 4-phenylcoumarin, volubolin, have been isolated.The structure of volubolin as 7-hydroxy-4-(3-hydroxy-4-methoxy-phenyl)-2H-1-benzopyran-2-one has been established on the basis of spectral and chemical evidence.Cooccurrence of 4-methyl- and 4-phenyl-coumarins with isoflavones is of biogenetic interest. - Key Word Index: Dalbergia volubilis; Leguminosae; young branches; 7-hydroxy-4-methyl coumarin; dalbergin; biochanin-A; 7-hydroxy-4-(3-hydroxy-4-methoxyphenyl)-2H-1-benzopyran-2-one.
Degradation and toxicity changes in aqueous solutions of chloroacetic acids by Fenton-like treatment using zero-valent iron
Macku'Ak, Tomas,Prousek, Josef,Smolinska, Miroslava,Olejnikova, Petra,Takacova, Alzbeta,Drtil, Miloslav
, p. 1594 - 1598 (2013)
Three priority pollutants, i.e. mono-, di-, and trichloroacetic acids, were degraded by the conventional Fenton AOP system (Fe2+ and H 2O2). The results obtained suggest that the degradation decreased in the order: monochl
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Andreasch
, p. 436 (1882)
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Electrochemical Strategy for the Simultaneous Production of Cyclohexanone and Benzoquinone by the Reaction of Phenol and Water
Wu, Ruizhi,Meng, Qinglei,Yan, Jiang,Liu, Huizhen,Zhu, Qinggong,Zheng, Lirong,Zhang, Jing,Han, Buxing
, p. 1556 - 1571 (2022/02/01)
Cyclohexanone and benzoquinone are important chemicals in chemical and manufacturing industries. The simultaneous production of cyclohexanone and benzoquinone by the reaction of phenol and water is an ideal route for the economical production of the two c
High-efficiency catalytic wet air oxidation of high salinity phenolic wastewater under atmospheric pressure in molten salt hydrate media
Tan, Hongzi,Wang, Shuai,Wang, Jinghua,Song, Feng,Sun, Xiuyu,Zhao, Rongrong,Zhang, Yuan,Cui, Hongyou
supporting information, p. 2167 - 2174 (2021/02/06)
An improved catalytic wet air oxidation (CWAO) process for high salinity phenolic wastewater is reported for the first time by using molten salt hydrates (MSHs) as reaction media. One feature of such a process is that it allows the operation to be conducted at atmospheric pressure owing to the temperature-increasing effect of MSHs. Another feature is that the inorganic salts in phenolic wastewater can be separated readily, taking advantage of the common-ion salting-out effect between inorganic salts and MSHs. Continuous catalytic oxidation degradation of the simulated high salinity phenolic wastewater demonstrated that more than 92% of phenol can be removed with chemical oxygen demand (COD) as high as 85% after reacting in CaCl2·3H2O medium at 150 °C with air as an oxidant. Meanwhile, the desalination efficiency of NaCl in continuous operation could reach up to 100%. It was found that CeCl3was an excellent catalyst for CWAO of phenol. XPS and UV-vis spectral characterization as well as radical scavenger experiments proved that [˙OH/Ce4+] was responsible for the synergistic catalytic degradation mechanism of phenol. Current work not only paves the way for developing a high-efficiency CWAO technology for concentrated organic wastewaters with high salinity, but also helps to better understand MSHs as reaction media.
Influence of Pd and Au on electrochemical valorization of glycerol over Ni-rich surfaces
Houache, Mohamed S.E.,Shubair, Asma,Sandoval, Mario G.,Safari, Reza,Botton, Gianluigi A.,Jasen, Paula V.,González, Estela A.,Baranova, Elena A.
, p. 1 - 13 (2021/03/03)
Herein we synthesized bi-metallic Pd@Ni and Au@Ni core-shell-like nanoparticles (NPs) for glycerol electrooxidation reaction (GEOR) in alkaline media. The morphological, structural and surface properties of the NPs were evaluated using a range of physicochemical techniques. The catalytic activity and stability were studied using the three-electrode electrochemical cell and 25 cm2- continuous electrolysis cell. Among different atomic ratios, Ni80Pd20 and Ni90Au10 nanoparticles showed the highest current densities which are ~4.5 and 4.2 times higher than spherical Ni, respectively. The addition of Pd and Au (a remarkable glycerate selectivity of ~73.1% and 65.7% for Ni80Pd20 and Ni90Au10 catalysts at 1.3 V and 50 °C, respectively. Notably, after 6 h of electrolysis Pd@Ni and Au@Ni tend to suppress the C-C bond cleavage, compared to Ni at any applied potentials and temperatures. The DFT calculations predicted that the addition of Pd or Au to Ni reduces the work function of M@Ni NPs, which strengthens the OH adsorption and enhances the removal of GEOR intermediates.
