Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Heterogeneous Catalytic Oxidation of Amides to Imides by Manganese Oxides.

ABSTRACT: Herein, we report a one-step peroxide mediated heterogeneous catalytic oxidation of amides to imides utilizing a series of manganese oxides. Among them, Cs/Mn2O3 was found to be the most active catalyst for the selective partial oxidation of N-benzylbenzamide to diphenyl imide. We have been able to apply an optimized oxidation method to other aromatic substrates. The feasibility of using air as an oxidant, the heterogeneous nature, inexpensive catalytic materials, respectable turnover numbers, and chemoselectivity to imides make this methodology an attractive choice for functional group transformations of amides to imides.

SUBMITTER: Biswas S

PROVIDER: S-EPMC6134084 | biostudies-other | 2018 Sep

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Heterogeneous Catalytic Oxidation of Amides to Imides by Manganese Oxides.

Biswas Sourav S Khanna Harshul S HS Nizami Quddus A QA Caldwell Donald R DR Cavanaugh Katherine T KT Howell Amy R AR Raman Sumathy S Suib Steven L SL Nandi Partha P

Scientific reports 20180911 1

Herein, we report a one-step peroxide mediated heterogeneous catalytic oxidation of amides to imides utilizing a series of manganese oxides. Among them, Cs/Mn2O3 was found to be the most active catalyst for the selective partial oxidation of N-benzylbenzamide to diphenyl imide. We have been able to apply an optimized oxidation method to other aromatic substrates. The feasibility of using air as an oxidant, the heterogeneous nature, inexpensive catalytic materials, respectab ...[more]

PMID: 30206248

Similar Datasets

Energetic basis of catalytic activity of layered nanophase calcium manganese oxides for water oxidation.

Project description:Previous measurements show that calcium manganese oxide nanoparticles are better water oxidation catalysts than binary manganese oxides (Mn3O4, Mn2O3, and MnO2). The probable reasons for such enhancement involve a combination of factors: The calcium manganese oxide materials have a layered structure with considerable thermodynamic stability and a high surface area, their low surface energy suggests relatively loose binding of H2O on the internal and external surfaces, and they possess mixed-valent manganese with internal oxidation enthalpy independent of the Mn(3+)/Mn(4+) ratio and much smaller in magnitude than the Mn2O3-MnO2 couple. These factors enhance catalytic ability by providing easy access for solutes and water to active sites and facile electron transfer between manganese in different oxidation states.

| S-EPMC3670370 | biostudies-literature

Mineral Manganese Oxides as Oxidation Catalysts: Capabilities in the CO-PROX Reaction.

Project description:Cryptomelane is an abundant mineral manganese oxide with unique physicochemical features. This work investigates the real capabilities of cryptomelane as an oxidation catalyst. In particular, the preferential CO oxidation (CO-PROX), has been studied as a simple reaction model. When doped with copper, the cryptomelane-based material has revealed a great potential, displaying a comparable activity to the high-performance CuO/CeO2. Despite stability concerns that compromise the primary catalyst reusability, CuO/cryptomelane is particularly robust in the presence of CO2 and H2O, typical components of realistic CO-PROX streams. The CO-PROX reaction mechanism has been assessed by means of isotopic oxygen pulse experiments. Altogether, CuO/CeO2 shows a greater oxygen lability, which facilitates lattice oxygen enrolment in the CO-PROX mechanism. In the case of CuO/cryptomelane, in spite of its lower oxygen mobility, the intrinsic structural water co-assists as active oxygen species involved in CO-PROX. Thus, the presence of moisture in the reaction stream turns out to be beneficial for the stability of the cryptomelane structure, besides aiding into the active oxygen restitution in the catalyst. Overall, this study proves that CuO/cryptomelane is a promising competitor to CuO/CeO2 in CO-PROX technology, whose implementation can bring the CO-PROX technology and H2 purification processes a more sustainable nature.

| S-EPMC8461565 | biostudies-literature

Homogeneous and heterogeneous catalytic reduction of amides and related compounds using molecular hydrogen.

Project description:Catalytic hydrogenation of amides is of great interest for chemists working in organic synthesis, as the resulting amines are widely featured in natural products, drugs, agrochemicals, dyes, etc. Compared to traditional reduction of amides using (over)stoichiometric reductants, the direct hydrogenation of amides using molecular hydrogen represents a greener approach. Furthermore, amide hydrogenation is a highly versatile transformation, since not only higher amines (obtained by C-O cleavage), but also lower amines and alcohols, or amino alcohols (obtained by C-N cleavage) can be selectively accessed by fine tuning of reaction conditions. This review describes the most recent advances in the area of amide hydrogenation using H2 exclusively and molecularly defined homogeneous as well as nano-structured heterogeneous catalysts, with a special focus on catalyst development and synthetic applications.

| S-EPMC7403344 | biostudies-literature

Heterogeneous Catalytic Oxidation of Ammonia by Various Transition Metals.

Project description:A well-known demonstration is adapted to simplify the illustration of heterogeneous catalytic oxidation of ammonia. Various metal catalyst wires are placed above the liquid level in a flask containing concentrated ammonia. After brief preheating, some metal wires continue to glow, providing visual evidence of an overall exothermic reaction taking place at the catalyst surface. Thermal heating by a butane flame prior to insertion and in situ resistive heating using a power supply yield identical results. Active catalysts are the group 9 and 10 elements Rh, Ir, Pd, and Pt. Besides the illustration of the Sabatier principle, the effect of the ammonia-to-oxygen ratio can also be visualized, and active metals vary in the production of a grayish smoke. These observations provide a starting point to discuss catalytic selectivity, a topic of great relevance to industrial catalytic oxidation of ammonia.

| S-EPMC6791287 | biostudies-literature

Catalytic Oxidation of Ammonia over Cerium-Modified Copper Aluminium Zinc Mixed Oxides.

Project description:Copper-containing mixed metal oxides are one of the most promising catalysts of selective catalytic oxidation of ammonia. These materials are characterized by high catalytic efficiency; however, process selectivity to dinitrogen is still an open challenge. The set of Cu-Zn-Al-O and Ce/Cu-Zn-Al-O mixed metal oxides were tested as catalysts of selective catalytic oxidation of ammonia. At the low-temperature range, from 250 °C up to 350 °C, materials show high catalytic activity and relatively high selectivity to dinitrogen. Samples with the highest Cu loading 12 and 15 mol.% of total cation content were found to be the most active materials. Additional sample modification by wet impregnation of cerium (8 wt.%) improves catalytic efficiency, especially N2 selectivity. The comparison of catalytic tests with results of physicochemical characterization allows connecting the catalysts efficiency with the form and distribution of CuO on the samples' surface. The bulk-like well-developed phases were associated with sample activity, while the dispersed CuO phases with dinitrogen selectivity. Material characterization included phase composition analysis (X-ray powder diffraction, UV-Vis diffuse reflectance spectroscopy), determination of textural properties (low-temperature N2 sorption, scanning electron microscopy) and sample reducibility analysis (H2 temperature-programmed reduction).

| S-EPMC8585330 | biostudies-literature

Electrochemical characterization of manganese oxides as a water oxidation catalyst in proton exchange membrane electrolysers.

Project description:The performance of four polymorphs of manganese (Mn) dioxides as the catalyst for the oxygen evolution reaction (OER) in proton exchange membrane (PEM) electrolysers was examined. The comparison of the activity between Mn oxides/carbon (Mn/C), iridium oxide/carbon (Ir/C) and platinum/carbon (Pt/C) under the same condition in PEM electrolysers showed that the γ-MnO2/C exhibited a voltage efficiency for water electrolysis comparable to the case with Pt/C, while lower than the case with the benchmark Ir/C OER catalyst. The rapid decrease in the voltage efficiency was observed for a PEM electrolyser with the Mn/C, as indicated by the voltage shift from 1.7 to 1.9 V under the galvanostatic condition. The rapid deactivation was also observed when Pt/C was used, indicating that the instability of PEM electrolysis with Mn/C is probably due to the oxidative decomposition of carbon supports. The OER activity of the four types of Mn oxides was also evaluated at acidic pH in a three-electrode system. It was found that the OER activity trends of the Mn oxides evaluated in an acidic aqueous electrolyte were distinct from those in PEM electrolysers, demonstrating the importance of the evaluation of OER catalysts in a real device condition for future development of noble-metal-free PEM electrolysers.

| S-EPMC6549974 | biostudies-literature

Heterogeneous-Driven Glutathione Oxidation: Defining the Catalytic Role of Chalcopyrite Nanoparticles.

Project description:Transition-metal nanocatalysis represents a novel alternative currently experiencing flourishing progress to tackle the tumor microenvironment (TME) in cancer therapy. These nanomaterials aim at attacking tumor cells using the intrinsic selectivity of inorganic catalysts. In addition, special attention to tune and control the release of these transition metals is also required. Understanding the chemical reactions behind the catalytic action of the transition-metal nanocatalysts and preventing potential undesired side reactions caused by acute cytotoxicity of the released ionic species represent another important field of research. Specifically, copper-based oxides may suffer from acute leaching that potentially may induce toxicity not only to target cancer cells but also to nearby cells and tissues. In this work, we propose the synthesis of chalcopyrite (CuFeS2) nanostructures capable of triggering two key reactions for an effective chemodynamic therapy (CDT) in the heterogeneous phase: (i) glutathione (GSH) oxidation and (ii) oxidation of organic substrates using H2O2, with negligible leaching of metals under TME-like conditions. This represents an appealing alternative toward the development of safer copper-iron-based nanocatalytic materials with an active catalytic response without incurring leaching side phenomena.

| S-EPMC10388351 | biostudies-literature

Synthesis and Characterization of Bismuth-Cerium Oxides for the Catalytic Oxidation of Diesel Soot.

Project description:In this paper, the syntheses of a set of cerium-bismuth mixed oxides with the formula Ce1-xBixO2-x/2, where the range of x is 0.0 to 1.0 in 10 mol% steps, via co-precipitation methods is described. Two synthesis routes are tested: The "normal" and the so called "reverse strike" (RS) co-precipitation route. The syntheses are performed with an automated synthesis robot. The activity for Diesel soot oxidation is measured by temperature programmed oxidation with an automated, serial thermogravimetric and differential scanning calorimetry system (TGA/DSC). P90 is used as a model soot. An automated and reproducible tight contact between soot and catalyst is used. The synthesized catalysts are characterized in terms of the specific surface area according to Brunauer, Emmett and Teller (SBET), as well as the dynamic oxygen storage capacity (OSCdyn). The crystalline phases of the catalysts are analysed by powder X-ray diffraction (PXRD) and Raman spectroscopy. The elemental mass fraction of the synthesized catalysts is verified by X-ray fluorescence (XRF) analysis. A correlation between the T50 values, OSCdyn and SBET has been discovered. The best catalytic performance is exhibited by the catalyst with the formula RS-Ce0.8Bi0.2Ox which is synthesized by the reverse strike co-precipitation route. Here, a correlation between activity, OSCdyn, and SBET can be confirmed based on structural properties.

| S-EPMC7143761 | biostudies-literature

Heterogeneous catalytic ozonation of ciprofloxacin in aqueous solution using a manganese-modified silicate ore.

Project description:Manganese modified silicate ore (MnSO) prepared using an impregnation method was used as a heterogeneous ozonation catalyst, and the catalytic activity was evaluated by the degradation of ciprofloxacin (CIP). The results showed that the manganese oxide was successfully loaded onto natural silicate ore (SO). The degradation and mineralization efficiencies of CIP were considerably improved in the presence of MnSO. Under optimal conditions, the CIP removal process followed the pseudo-first-order reaction model well. The degradation rate constant of MnSO/O3 was 1.7 times and 3.3 times higher than those of SO/O3 and only O3, respectively. During the ozonation of the CIP aqueous solution in the presence of MnSO, the TOC removal rate reached 61.2% at 60 min, but was only 30.8% using ozonation alone. The addition of tert-butanol (TBA) significantly inhibited the degradation efficiency of CIP, which indicated that catalytic ozonation of MnSO followed a hydroxyl radical (·OH) reaction mechanism. Furthermore, MnSO showed great stability and durability over several reaction cycles.

| S-EPMC9086485 | biostudies-literature

Heterogeneous Reaction of SO2 on Manganese Oxides: the Effect of Crystal Structure and Relative Humidity.

Project description:Manganese oxides from anthropogenic sources can promote the formation of sulfate through catalytic oxidation of SO2. In this study, the kinetics of SO2 reactions on MnO2 with different morphologies (?, ?, ? and ?) was investigated using flow tube reactor and in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). Under dry conditions, the reactivity towards SO2 uptake was highest on ?-MnO2 but lowest on ?-MnO2, with a geometric uptake coefficient (?obs) of (2.42?±?0.13) ×10-2 and a corrected uptake coefficient (?c) of (1.48?±?0.21) ×10-6 for the former while ?obs of (3.35?±?0.43) ×10-3 and ?c of (7.46?±?2.97) ×10-7 for the latter. Under wet conditions, the presence of water altered the chemical form of sulfate and was in favor for the heterogeneous oxidation of SO2. The maximum sulfate formation rate was reached at 25% RH and 45% for ?-MnO2 and ?-MnO2, respectively, possibly due to their different crystal structures. The results suggest that morphologies and RH are important factors influencing the heterogeneous reaction of SO2 on mineral aerosols, and that aqueous oxidation process involving transition metals of Mn might be a potential important pathway for SO2 oxidation in the atmosphere.

| S-EPMC5495761 | 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