105938-46-3Relevant academic research and scientific papers
Carbon exchange in hot alkaline degradation of glucose
Ellis, Amanda V.,Wilson, Michael A.
, p. 8469 - 8474 (2002)
The decomposition of 1-13C-D-glucose, 6-13C-D-glucose, and 1-13C-sodium lactate has been studied in hot (145 ± 3 °C) alkaline (3.5 M) sodium hydroxide solution in order to understand the mechanisms of carbon exchange in th
Microgel-stabilized gold nanoclusters: Powerful "quasi-homogeneous" catalysts for the aerobic oxidation of alcohols in water
Biffis, Andrea,Cunial, Sara,Spontoni, Paolo,Prati, Laura
, p. 1 - 6 (2007)
Gold nanoclusters of small size (2.5 nm) and narrow size distribution were synthesized in solution using tailor-made soluble cross-linked polymers (microgels) as exotemplates and stabilizers. The resulting microgel-stabilized nanoclusters could be conveniently isolated by precipitation, stored in the solid state, and redispersed in water and polar organic solvents. They were found to exhibit remarkable catalytic activity (average TOF up to 960 h-1) in the aerobic oxidation of benzylic and aliphatic alcohols and also of polyols in water under mild conditions (50-70 °C, 1-3 atm O2).
Homogeneous Reforming of Aqueous Ethylene Glycol to Glycolic Acid and Pure Hydrogen Catalyzed by Pincer-Ruthenium Complexes Capable of Metal–Ligand Cooperation
Zou, You-Quan,von Wolff, Niklas,Rauch, Michael,Feller, Moran,Zhou, Quan-Quan,Anaby, Aviel,Diskin-Posner, Yael,Shimon, Linda J. W.,Avram, Liat,Ben-David, Yehoshoa,Milstein, David
, p. 4715 - 4722 (2021)
Glycolic acid is a useful and important α-hydroxy acid that has broad applications. Herein, the homogeneous ruthenium catalyzed reforming of aqueous ethylene glycol to generate glycolic acid as well as pure hydrogen gas, without concomitant CO2 emission, is reported. This approach provides a clean and sustainable direction to glycolic acid and hydrogen, based on inexpensive, readily available, and renewable ethylene glycol using 0.5 mol % of catalyst. In-depth mechanistic experimental and computational studies highlight key aspects of the PNNH-ligand framework involved in this transformation.
Determination of cotton-bound glyoxal via an internal Cannizzaro reaction by means of high-performance liquid chromatography
Schramm, Christian,Rinderer, Beate
, p. 5829 - 5833 (2000)
Glyoxal, a non-formaldehyde cross-linking agent, was applied in combination with aluminum sulfate hexadecahydrate to impart durable-press properties to cellulosic materials. The cotton fabric was impregnated with a pad bath formulation containing 6% (w/w) glyoxal and 4.5% (w/w) aluminum sulfate hexadecahydrate. The curing process was conducted at 140°C for 3 min, thus affecting a cross-linkage between the cellulose chains. For the first time, a chromatographic method is presented that enables both qualitative and quantitative analysis of the portion of glyoxal that has reacted with the cellulosic material. For this purpose, the glyoxal-treated fabric was treated with an NaOH solution (c = 4 mol L-1) at 100°C for 20 min. As a result, glyoxal was extracted from the cellulosic sample and converted into glycolate via an internal Cannizzaro reaction. Subsequently, the glycolate was analyzed chromatographically using the strong cation-exchange column Aminex HPX-87H as the stationary phase and sulfuric acid as the mobile phase. The detection limit was 1.87 mg L-1 (UV detection). The recovery was 85%. Dry crease wrinkle recovery measurements gave evidence that the cross-linkage was removed completely. The application of the analytical technique developed in the present study demonstrated that the amount of glyoxal that had reacted with the cellulose was 15.7 ± 0.72 mg/g of fabric. In addition, glycolate thus formed was well separated from non-formaldehyde durable-press finishing agents based on polycarboxylic acids such as 1,2,3,4-butanetetracarboxylic acid or citric acid.
Efficient and Bio-inspired Conversion of Cellulose to Formic Acid Catalyzed by Metalloporphyrins in Alkaline Solution
Liu, Qiang,Zhou, Doudou,Li, Zongxiang,Luo, Weiping,Guo, Cancheng
, p. 1063 - 1068 (2017)
A bio-inspired approach for efficient conversion of cellulose to formic acid (FA) was developed in an aqueous alkaline medium. Metalloporphyrins mimicking cytochrome P450 exhibit efficiently and selectively catalytic performance in catalytic conversion of cellulose. High yield of FA about 63.7% was obtained by using sulfonated iron(III) porphyrin as the catalyst and O2 as the oxidant. Iron(III)-peroxo species, TSPPFeIIIOO?, was involved to cleave the C-C bonds of gluconic acid to FA in this catalytic system. This approach used relatively high concentration of cellulose and ppm concentration of catalyst. This work may provide a bio-inspired route to efficient conversion of cellulose to FA.
Chemometric approaches on glycerol oxidation with H2O 2 over supported gold nanoparticles
Nunes, Cleiton A.,Guerreiro, Mário C.
, p. 145 - 151 (2013)
This paper reports a chemometric study of effects of the catalyst preparation method and reaction conditions on the efficiency of glycerol oxidation catalyzed by gold nanoparticles supported on activated carbon using H2O2 as oxidant. Factorial designs and principal component analysis were used for the evaluation of experimental conditions and reaction performance. Evaluating catalyst preparation conditions we found that larger Au nanoparticles are obtained using HAuCl4 in higher concentration. Glycerol conversion and production of glycerate and tartronate were higher using catalysts prepared with low polyvinyl alcohol (PVA) to Au ratio and low Au content. Higher HAuCl4 concentrations resulted in larger Au nanoparticles, which contributed to higher glycolate production. Evaluating reaction conditions we found that the influence of H2O2 to glycerol ratio was insignificant. Glycerol conversion and production of glycerate and tartronate were higher at lower temperature. Increasing H 2O2 to glycerol ratio contributed to higher glycolate production. Glycerol to Au ratio has a smaller influence on the reaction course.
Gold on carbon as a new catalyst for selective liquid phase oxidation of diols
Prati, Laura,Rossi, Michele
, p. 552 - 560 (1998)
Catalytic oxidation of vicinal diols to α-hydroxy carboxylates with dioxygen in alkaline solution has been performed by using gold based catalysts. The optimization of the catalytic system has highlighted the influence of the support and preparation method on both activity and selectivity. Under mild conditions (T = 343-363 K, pO2 = 300 kPa (absolute)) high selectivities (90-100%) toward monooxygenation in the cases of ethane-1,2-diol and propane-1,2-diol were achieved at high diol conversions (80-94%). The racemization of optically active propane-1,2-diol during its oxidation as well as isotopic H-D exchange experiments allowed us to deduce new features in the mechanism of diol oxidation and concerning the dependence of selectivity on reaction conditions. The recycling of gold on carbon catalyst revealed its good resistance toward deactivation, greater than palladium or platinum on carbon catalysts which were respectively affected by metal leaching and a considerable loss of selectivity.
Hydrolysis kinetics of chloroacetic acid with sodium hydroxide under strong alkaline conditions
Li, Wenze,Chang, Shaoqing,Chen, Xin,Qi, Xuan,Sun, Hong-Bin
, p. 3404 - 3406 (2014)
The hydrolysis of chloroacetic acid and sodium hydroxide is carried out at 45-85 °C by using equal mole of sodium chloroacetate and alkali. Using reasonable approximation, the hydrolysis reaction is proved to be a second-order reaction when the conversion is less than 95 % and the kinetic rate coefficients are determined. The activate energy is calculated 103 kJ mol-1.
Bismuth as a modifier of Au-Pd catalyst: Enhancing selectivity in alcohol oxidation by suppressing parallel reaction
Villa, Alberto,Wang, Di,Veith, Gabriel M.,Prati, Laura
, p. 73 - 80 (2012)
Bi has been widely employed as a modifier for Pd and Pt based catalyst mainly in order to improve selectivity. We found that when Bi was added to the bimetallic system AuPd, the effect on activity in alcohol oxidation mainly depends on the amount of Bi regardless its position, being negligible when Bi was 0.1 wt% and detectably negative when the amount was increased to 3 wt%. However, the selectivity of the reactions notably varied only when Bi was deposited on the surface of metal nanoparticles suppressing parallel reaction in both benzyl alcohol and glycerol oxidation. After a careful characterization of all the catalysts and additional catalytic tests, we concluded that the Bi influence on the activity of the catalysts could be ascribed to electronic effect whereas the one on selectivity mainly to a geometric modification. Moreover, the Bi-modified AuPd/AC catalyst showed possible application in the production of tartronic acid, a useful intermediate, from glycerol.
Preparation method for 2,4-dichlorophenoxyacetic acid
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Paragraph 0037; 0038; 0040; 0041; 0042; 0043; 0044; 0045, (2018/09/28)
The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: A) reacting a divalent salt of glycolic acid as shown in a formula(I) with 1,2,4-trichlorobenzene under the action of a catalyst so as to produce 2,4-dichlorophenoxyacetate as shown in a formula (II); and B) acidizing 2,4-dichlorophenoxyacetate so as to obtain 2,4-dichlorophenoxyacetic acid. According to the invention, 1,2,4-trichlorobenzene is creatively used for replacing phenol and chlorophenol and subjected to a condensation reaction with glycolate so as toproduce 2,4-dichlorophenoxyacetate, and hydrolysis is carried out so as to prepare 2,4-dichlorophenoxyacetic acid; so such a technical scheme effectively avoids the usage of phenol or chlorophenol, overcomes the problems of peculiar smell of an operation place and production of waste gas, waste water and industrial residues, greatly improves the operation environment of the operation place and produces good environmental protection benefits, and the reaction has high yield and purity.
