Browse
Submit Data
Databases
API
Help

Dataset Information

22 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Hydrogenation of Lactic Acid to 1,2-Propanediol over Ru-Based Catalysts.

ABSTRACT: The catalytic hydrogenation of lactic acid to 1,2-propanediol with supported Ru catalysts in water was investigated. The influence of catalyst support (activated carbon, ?-Al₂O₃, SiO₂, TiO₂, and CeO₂) and promoters (Pd, Au, Mo, Re, Sn) on the catalytic performance was evaluated. Catalytic tests revealed that TiO₂ yields the best Ru catalysts. With a monometallic Ru/TiO₂ catalyst, a 1,2-propanediol yield of 70?% at 79?% lactic acid conversion was achieved at 130?°C after 20?h reaction. Minor byproducts of the hydrogenation reaction were propionic acid, ethanol, 1-propanol, and 2-propanol. For the bimetallic catalysts, the addition of Pd and Au slightly enhanced the performance of Ru/TiO₂, whereas the addition of common hydrogenation promoters such as Re, Mo, and Sn impaired the activity.

SUBMITTER: Liu K

PROVIDER: S-EPMC5838540 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Catalytic Conversion of Biomass-Derived 1,2-Propanediol to Propylene Oxide over Supported Solid-Base Catalysts.

Project description:A series of supported alkali metal salts were investigated as catalysts to produce propylene oxide (PO) from biomass-derived 1,2-propanediol via dehydrative epoxidation in a solid-gas reaction system. The effects of supports, cations, and anions in the alkali metal salts and calcination temperature were investigated by X-ray diffraction and CO2-temperature-programmed desorption. The results indicate the catalysts with relative mild basicity having higher yields of PO. The highest yield of PO is 58.2% from reactions at 400 °C at an atmospheric pressure over KNO3/SiO2. In addition, the catalyst could be reused after calcination in air at 550 °C.

| S-EPMC6644628 | biostudies-literature

Mg(OH)2 -Facilitated Liquid-Phase Conversion of Lactic Acid into 1,2-Propanediol over Cu: An Experimental and Theoretical Study.

Project description:Mg(OH)2 is found to exhibit superior performance in the liquid-phase conversion of lactic acid (LA) into 1,2-propanediol over Cu. A conversion of 90?% with a selectivity of 98?% is achieved at 513?K and 5?MPa H2 . Mg(LA)2 could be identified as a crucial intermediate in this reaction, as it undergoes faster conversion than the combination of LA and Mg(OH2 ) and regeneration of Mg(OH)2 through the conversion of Mg(LA)2 as a substrate. DFT calculations reveal that the energetic span of the reaction decreases from 46.6?kcal?mol-1 catalyzed with no cation to 43.6?kcal?mol-1 with [Mg(OH)]+ , confirming the facilitating effect of Mg(OH)2 .

| S-EPMC6973064 | biostudies-literature

Heterophase-structured nanocrystals as superior supports for Ru-based catalysts in selective hydrogenation of benzene.

Project description:ZrO2 heterophase structure nanocrystals (HSNCs) were synthesized with tunable ratios of monoclinic ZrO2 (m-ZrO2) to tetragonal ZrO2 (t-ZrO2). The phase mole ratio of m-ZrO2 versus t-ZrO2 in ZrO2 HSNCs was tuned from 40% to 100%. The concentration of the surface hydroxyl groups on m-ZrO2 is higher than that on t-ZrO2. ZrO2 HSNCs have different surface hydroxyl groups on two crystalline phases. This creates more intimate synergistic effects than their single-phase counterparts. The ZrO2 HSNCs were used as effective supports to fabricate heterophase-structured Ru/ZrO2 catalysts for benzene-selective hydrogenation. The excellent catalytic performance including high activity and selectivity is attributed to the heterogeneous strong/weak hydrophilic interface and water layer formed at the m-ZrO2/t-ZrO2 catalyst junction.

| S-EPMC5216362 | biostudies-literature

CO2 Hydrogenation to Methanol over Mesoporous SiO2-Coated Cu-Based Catalysts

Project description: Not available

| S-EPMC11342343 | biostudies-literature

Transient Ru-methyl formate intermediates generated with bifunctional transfer hydrogenation catalysts.

Project description:Desorption electrospray ionization (DESI) coupled to high-resolution Orbitrap mass spectrometry (MS) was used to study the reactivity of a (β-amino alcohol)(arene)RuCl transfer hydrogenation catalytic precursor in methanol (CH(3)OH). By placing [(p-cymene)RuCl(2)](2) on a surface and spraying a solution of β-amino alcohol in methanol, two unique transient intermediates having lifetimes in the submillisecond to millisecond range were detected. These intermediates were identified as Ru (II) and Ru (IV) complexes incorporating methyl formate (HCOOCH(3)). The Ru (IV) intermediate is not observed when the DESI spray solution is sparged with Ar gas, indicating that O(2) dissolved in the solvent is necessary for oxidizing Ru (II) to Ru (IV). These proposed intermediates are supported by high-resolution and high mass accuracy measurements and by comparing experimental to calculated isotope profiles. Additionally, analyzing the bulk reaction mixture using gas chromatography-MS and nuclear magnetic resonance spectroscopy confirms the formation of HCOOCH(3). These results represent an example that species generated from the (β-amino alcohol)(arene)RuCl (II) catalytic precursor can selectively oxidize CH(3)OH to HCOOCH(3). This observation leads us to propose a pathway that can compete with the hydrogen transfer catalytic cycle. Although bifunctional hydrogen transfer with Ru catalysts has been well-studied, the ability of DESI to intercept intermediates formed in the first few milliseconds of a chemical reaction allowed identification of previously unrecognized intermediates and reaction pathways in this catalytic system.

| S-EPMC3289342 | biostudies-literature

CO2 Hydrogenation over Unsupported Fe-Co Nanoalloy Catalysts.

Project description:The thermo-catalytic synthesis of hydrocarbons from CO2 and H2 is of great interest for the conversion of CO2 into valuable chemicals and fuels. In this work, we aim to contribute to the fundamental understanding of the effect of alloying on the reaction yield and selectivity to a specific product. For this purpose, Fe-Co alloy nanoparticles (nanoalloys) with 30, 50 and 76 wt% Co content are synthesized via the Inert Gas Condensation method. The nanoalloys show a uniform composition and a size distribution between 10 and 25 nm, determined by means of X-ray diffraction and electron microscopy. The catalytic activity for CO2 hydrogenation is investigated in a plug flow reactor coupled with a mass spectrometer, carrying out the reaction as a function of temperature (393-823 K) at ambient pressure. The Fe-Co nanoalloys prove to be more active and more selective to CO than elemental Fe and Co nanoparticles prepared by the same method. Furthermore, the Fe-Co nanoalloys catalyze the formation of C2-C5 hydrocarbon products, while Co and Fe nanoparticles yield only CH4 and CO, respectively. We explain this synergistic effect by the simultaneous variation in CO2 binding energy and decomposition barrier as the Fe/Co ratio in the nanoalloy changes. With increasing Fe content, increased activation temperatures for the formation of CH4 (from 440 K to 560 K) and C2-C5 hydrocarbons (from 460 K to 560 K) are observed.

| S-EPMC7408123 | biostudies-literature

Conversion of biomass-derived sorbitol to glycols over carbon-materials supported Ru-based catalysts.

Project description:Ruthenium (Ru) supported on activated carbon (AC) and carbon nanotubes (CNTs) was carried out in the hydrogenolysis of sorbitol to ethylene glycol (EG) and 1,2-propanediol (1,2-PD) under the promotion of tungsten (WOx) species and different bases. Their catalytic activities and glycols selectivities strongly depended on the support properties and location of Ru on CNTs, owning to the altered metal-support interactions and electronic state of ruthenium. Ru located outside of the tubes showed excellent catalytic performance than those encapsulated inside the nanotubes. Additionally, the introduction of WOx into Ru/CNTs significantly improved the hydrogenolysis activities, and a complete conversion of sorbitol with up to 60.2% 1,2-PD and EG yields was obtained on RuWOx/CNTs catalyst upon addition of Ca(OH)2. Stability study showed that this catalyst was highly stable against leaching and poisoning and could be recycled several times.

| S-EPMC4649675 | biostudies-literature

Pollutant Abatement of Nitrogen-Based Fuel Effluents over Mono- and Bimetallic Pt/Ru Catalysts.

Project description:Mono- and bimetallic alloy Pt and Ru catalysts supported on γ-Al2O3 have been investigated for the reduction of pollutants (NO x , NH3, and CO) generated during the continuous combustion of an aqueous urea ammonium nitrate fuel. A Pt/Ru alloy with a Pt25/Ru75 atomic ratio has been found to have higher activity and selectivity than those of a 50/50 alloy and monometallic catalysts. Among monometallic catalysts, Ru was more selective toward N2 formation, whereas Pt showed a higher selectivity toward NH3 formation. For Ru, it was observed that the oxidizing atmosphere of NO x pollutants caused the formation of RuO2, whereas Ru in the Pt/Ru alloy was stable under these conditions. Temperature (250-500 °C) and pressure (1-8 MPa) studies over Ru and 25/75 Pt/Ru have concluded that the alloy catalyst at 400 °C and 5 MPa reduced the pollutants to a minimum level with high yields of N2 (99.7%) and CO2 (99.9%). It was also observed that the 25/75 Pt/Ru catalyst remained stable up to 100 h of thermal treatment at 400 °C. Minimal pollutants were obtained at a weight hourly space velocity = 11 822 h-1. Characterization studies of the spent catalyst showed that metal particles were sintered over a period of time (8 h) and the γ-Al2O3 support was transformed into θ- and α-phases under the hydrothermal reaction conditions.

| S-EPMC6645125 | biostudies-literature

1,2-Dichloroethane Deep Oxidation over Bifunctional Ru/Ce x Al y Catalysts.

Project description:Ru/Ce x Al y catalysts were synthesized with impregnation of RuCl3 aqueous solution on Ce x Al y (Al2O3-CeO2) and used in 1,2-dichloroethane (1,2-DCE) oxidation. Characterization by X-ray diffraction, Raman, NH3-temperature-programmed desorption (TPD), CO2-TPD, X-ray photoelectron spectroscopy, and H2-temperature-programmed reduction indicates that CeO2 exists as a form of face-centered cubic fluorite structure, whereas the chemical states and the structure of Ru species are dependent on the Ce content. The reducibility and acidity of catalysts increase with Ce/Ce + Al ratio. However, the latter is promoted only in a Ce/Ce + Al range of 0-0.25 and then decreases quickly. Ru/Ce x Al y catalysts have considerable activity for 1,2-DCE combustion. TOFRu of 1,2-DCE oxidation increases with strong acid, which is ascribed to a synergy of reducibility and acidity. Ru greatly inhibits the chlorination through the decreases in both Cl deposition and CH2=CHCl formation. High stability of Ru/Ce10Al90 maintains at 280 °C for at least 25 h with CO2 selectivity of 99% or higher. In situ Fourier transform infrared spectroscopy indicates that 1,2-DCE dissociates to form ClCH2-CH2O- species, which is an intermediate species for the production of CH3CHO and CH2=CHCl, the former responsible for deep oxidation.

| S-EPMC6645373 | biostudies-literature

Metabolic engineering of Escherichia coli for the de novo stereospecific biosynthesis of 1,2-propanediol through lactic acid.

Project description:1,2-propanediol (1,2-PDO) is an industrial chemical with a broad range of applications, such as the production of alkyd and unsaturated polyester resins. It is currently produced as a racemic mixture from nonrenewable petroleum-based feedstocks. We have reported a novel artificial pathway for the biosynthesis of 1,2-PDO via lactic acid isomers as the intermediates. The pathway circumvents the cytotoxicity issue caused by methylglyoxal intermediate in the naturally existing pathway. Successful E. coli bioconversion of lactic acid to 1,2-PDO was shown in previous report. Here, we demonstrated the engineering of E. coli host strains for the de novo biosynthesis of 1,2-PDO through this pathway. Under fermenter-controlled conditions, the R-1,2-PDO was produced at 17.3?g/L with a molar yield of 42.2% from glucose, while the S-isomer was produced at 9.3?g/L with a molar yield of 23.2%. The optical purities of the two isomers were 97.5% ee (R) and 99.3% ee (S), respectively. To the best of our knowledge, these are the highest titers of 1,2-PDO biosynthesized by either natural producer or engineered microbial strains that are published in peer-reviewed journals.

| S-EPMC6304458 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data