Oxidation of 1,2-Propanediol to Lactic Acid under Novel Supported Au Catalysts and Reaction Kinetics

This work demonstrates that 5wt% gold catalysts supported on Al2O3 and TiO2 nanopowders as well as on TiO2 nanofibers are active in the 1,2-propanediol (1,2-PDO) oxidation to lactic acid. The influence of catalysts different parameters and reaction conditions on 1,2-PDO conversion and oxidation process selectivity was studied. The best result was achieved using 5wt%Au/TiO2 catalyst over the following oxidation parameters: c0(1,2-PDO) = 0.3 mol/L, n (1,2-PDO)/n (Au) = 4000 mol/mol, p (O2) = 6 bar, c0(NaOH) = 2 mol/L, t = 60 °C: 1,2-propanediol conversion was 98 % and lactic acid selectivity 89 %.

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Kinetic Model of the 1,2-Propanediol Oxidation Reaction in the Presence of 3wt%Pd/α-Al2O3 Catalyst

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.903.143 ◽

2021 ◽

Vol 903 ◽

pp. 143-148

Author(s):

Svetlana Cornaja ◽

Svetlana Zhizhkuna ◽

Jevgenija Vladiko

Keyword(s):

Activation Energy ◽

Lactic Acid ◽

Kinetic Model ◽

Catalytic Oxidation ◽

Molecular Oxygen ◽

Oxidation Reaction ◽

Main Product ◽

Oxidation Process ◽

Water Solution ◽

Reaction Conditions

Supported 3wt%Pd/α-Al₂O₃ catalyst was tested in selective oxidation of 1,2-propanediol by molecular oxygen. It was found that the catalyst is active in an alkaline water solution. Lactic acid was obtained as the main product of the reaction. Influence of different reaction conditions on 1,2-PDO conversion and oxidation process selectivity was studied. Partial kinetic orders of the reaction with respect to 1,2-propanediol, c0(NaOH), p(O2), n(1,2-PDO)/n(Pd)) were determined and an experimental kinetic model of the catalytic oxidation reaction was obtained. Activation energy of the process was calculated and was found to be about 53 ± 5 kJ/mol.

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Study on Pretreatment of Dye Wastewater by Fenton Oxidation Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.627.378 ◽

2012 ◽

Vol 627 ◽

pp. 378-381

Author(s):

Bi Rong Wang

Keyword(s):

Reaction Time ◽

Oxidation Process ◽

Removal Rate ◽

Fenton Oxidation ◽

Dye Wastewater ◽

Dyeing Wastewater ◽

Reaction Conditions ◽

Fenton Oxidation Process

Fenton pretreatment has been used for treating dye wastewater. The effects of the dos of H2O2 and FeSO4, reaction time and pH on the removal COD were investigated. It was found that, when the reaction conditions are as follows: COD 2850 mg/L dyeing wastewater, the dosage of H2O2 is 140mmol/L, FeSO4 17.02 mmol/L, pH 7.6, and reaction time 1.0 h, the CODcr of dye wastewater removal rate of up to 70%. Fenton pretreatment process of dye wastewater has a broad prospect.

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End Functionalization by Ring Opening Polymerization: Influence of Reaction Conditions on the Synthesis of End Functionalized Poly(lactic Acid)

Journal of the Brazilian Chemical Society ◽

10.21577/0103-5053.20170118 ◽

2017 ◽

Cited By ~ 1

Author(s):

Luis Icart ◽

Edson Fernandes ◽

Lissette Agüero ◽

Maelia Cuesta ◽

Dionisio Silva ◽

...

Keyword(s):

Lactic Acid ◽

Ring Opening ◽

Ring Opening Polymerization ◽

Poly Lactic Acid ◽

Reaction Conditions

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Cyclic Oxidation of Titanium Grade 2

Materials ◽

10.3390/ma13235431 ◽

2020 ◽

Vol 13 (23) ◽

pp. 5431

Author(s):

Krzysztof Aniołek ◽

Adrian Barylski ◽

Marian Kupka ◽

Grzegorz Dercz

Keyword(s):

Cyclic Oxidation ◽

Considerable Increase ◽

Oxidation Process ◽

Surface Hardness ◽

Oxide Layers ◽

Arrhenius Diagram ◽

Oxide Particles ◽

Titanium Grade ◽

Oxidation Parameters ◽

Tio2 Rutile

This paper presents the results of research into the cyclic oxidation of titanium Grade 2. The value of titanium Grade 2 oxidation activation energy was determined based on an analysis of the Arrhenius diagram. The result was 205.3 kJ/mol. After cyclic oxidation at a temperature of 600 °C, the presence of oxides in an acicular system was observed on the surface. The specimen surface after oxidation at 650 °C was characterised by the presence of fine oxide particles, while after oxidation at 700 °C, the obtained oxide layer was composed of large oxide particles. The layers obtained after oxidation at 600 °C had the lowest thickness (1.26 and 2.12 µm), while those obtained at 700 °C had the highest thickness (5.17 and 9.45 µm). Examination of the phase composition after cyclic oxidation showed that the oxide layers obtained at temperatures of 600, 650 and 700 °C were composed of TiO2 (rutile) only. No presence of other phases was found. The oxide layers formed in the cyclic oxidation process were characterised by different thicknesses, depending on the oxidation parameters. It was found that cyclic oxidation contributed to a considerable increase in the surface hardness of titanium Grade 2.

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A self-adjusting platinum surface for acetone hydrogenation

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1917110117 ◽

2020 ◽

Vol 117 (7) ◽

pp. 3446-3450 ◽

Cited By ~ 4

Author(s):

Benginur Demir ◽

Thomas Kropp ◽

Keishla R. Rivera-Dones ◽

Elise B. Gilcher ◽

George W. Huber ◽

...

Keyword(s):

Reaction Kinetics ◽

Density Functional ◽

Surface Coverage ◽

Binding Energies ◽

Microkinetic Modeling ◽

Reaction Conditions ◽

Platinum Surface ◽

Kinetics Parameters ◽

Supported Platinum Catalysts ◽

Wide Range

We show that platinum displays a self-adjusting surface that is active for the hydrogenation of acetone over a wide range of reaction conditions. Reaction kinetics measurements under steady-state and transient conditions at temperatures near 350 K, electronic structure calculations employing density-functional theory, and microkinetic modeling were employed to study this behavior over supported platinum catalysts. The importance of surface coverage effects was highlighted by evaluating the transient response of isopropanol formation following either removal of the reactant ketone from the feed, or its substitution with a similarly structured species. The extent to which adsorbed intermediates that lead to the formation of isopropanol were removed from the catalytic surface was observed to be higher following ketone substitution in comparison to its removal, indicating that surface species leading to isopropanol become more strongly adsorbed on the surface as the coverage decreases during the desorption experiment. This phenomenon occurs as a result of adsorbate–adsorbate repulsive interactions on the catalyst surface which adjust with respect to the reaction conditions. Reaction kinetics parameters obtained experimentally were in agreement with those predicted by microkinetic modeling when the binding energies, activation energies, and entropies of adsorbed species and transition states were expressed as a function of surface coverage of the most abundant surface intermediate (MASI, C3H6OH*). It is important that these effects of surface coverage be incorporated dynamically in the microkinetic model (e.g., using the Bragg–Williams approximation) to describe the experimental data over a wide range of acetone partial pressures.

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Lactic acid demineralization of green crab (Carcinus maenas) shells: effect of reaction conditions and isolation of an unusual calcium complex

Green Chemistry Letters and Reviews ◽

10.1080/17518253.2015.1119891 ◽

2016 ◽

Vol 9 (1) ◽

pp. 1-11 ◽

Cited By ~ 5

Author(s):

Bradley H. C. Greene ◽

Katherine N. Robertson ◽

John C. O'C. Young ◽

Jason A. C. Clyburne

Keyword(s):

Lactic Acid ◽

Carcinus Maenas ◽

Green Crab ◽

Reaction Conditions

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ChemInform Abstract: COMPLEXATION OF PHENYLBORONIC ACID WITH LACTIC ACID, STABILITY CONSTANT AND REACTION KINETICS

Chemischer Informationsdienst ◽

10.1002/chin.197444300 ◽

1974 ◽

Vol 5 (44) ◽

pp. no-no

Author(s):

SAMUEL FRIEDMAN ◽

BENJAMIN PACE ◽

RICHARD PIZER

Keyword(s):

Lactic Acid ◽

Stability Constant ◽

Reaction Kinetics ◽

Phenylboronic Acid ◽

Acid Stability

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Oxidation Kinetics of 1,2-Propanediol in the Presence of Pd and Pt Catalysts

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.850.48 ◽

2020 ◽

Vol 850 ◽

pp. 48-53

Author(s):

Svetlana Chornaja ◽

Svetlana Zhizhkuna ◽

Jevgenija Vladiko ◽

Reinis Drunka ◽

Aija Krūmiņa

Keyword(s):

Lactic Acid ◽

Molecular Oxygen ◽

Selective Oxidation ◽

Oxidation Kinetics ◽

Main Product ◽

Pt Catalysts ◽

Acid Yield ◽

Active Metal ◽

Oxidation Parameters ◽

Kinetics Of

1.25 – 5wt%Pt/Al2O3, 1.25 – 5wt%Pd/Al2O3, 1wt%Pd/TiO2, 1 – 5wt%Pd/TiO2-NF, 1.25wt%Pt+1.25wt%Pd/Al2O3, 5wt%Pt/SiO2, 5wt%Pt/C catalysts were synthesised and tested in the selective oxidation of 1,2-propanediol by molecular oxygen. It was found that all catalysts were active in alkaline water solutions; lactic acid was obtained as the main product of the reaction. The conversion of 1,2-propandiol and the yield of lactic acid depended on the content of active metal in the catalysts. The most active for the oxidation of 1,2-propandiol were palladium-containing catalysts supported on TiO2 nanofibers (Pd/TiO2-NF). The highest 1,2-propanediol conversion (100 %) and lactic acid yield (96 %) were obtained using the 5wt%Pd/TiO2-NF catalyst at the following oxidation parameters: c0(1,2-propanediol) = 0.3 mol/L, P(O2) = 1 atm, n (1,2-propanediol)/n (Pd) = 500 mol/mol, t = 60 °C, c0(NaOH) = 1.5 mol/L.

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