Supported Liquid Phase Catalysis Research Articles

A Review of Synthetic Application of Homogeneous, Heterogenised‐Homogeneous, and Microwave‐Assisted Catalytic Carbonylation of Selected Substrates

AbstractCatalytic carbonylation has gained a lot of interest over the past 20 years. It produced various pharmaceuticals, agrochemicals, and intermediates that can made through this process. The carbonylation process is the most straightforward method to insert CO into any organic substrate using a simple carbonyl source, i. e., CO gas. Apart from gaseous CO, many techniques have devised for producing CO in situ using surrogates such as HCOOH, DMF, Formic acid, Phenyl Formate, Oxalic acid, and Chloroform. Several carbonylation methods, such as aminocarbonylation, alkoxycarbonylation, double carbonylation, and oxidative carbonylation, provide viable and appealing substitutes for conventional synthetic methods on a commercial or laboratory scale. Many recent studies focus on catalyst‐product separation, catalyst recoverability, and reusability in these reactions. Therefore, advancements in using different approaches, such as supported liquid phase catalysis and biphasic catalysis, to anchor homogeneous catalysts are becoming increasingly important. These carbonylation methods are easy to use, cost‐effective, and do not require ligands. They also produce excellent yields of the products necessary. Using phosphine ligands has drawbacks, including high work‐up costs, laborious work‐up techniques, and sensitivity to air and moisture. Several phosphine‐free carbonylation pathways offer affordable and straightforward ways to accomplish these changes without phosphine ligands. This review summarizes the synthetic application of homogeneous and immobilized catalysts in producing carboxylic acid derivatives and heterocycles that have medicinal properties.

Cover Feature: Oxygen‐Functionalized Boron Nitride for the Oxidative Dehydrogenation of Propane – The Case for Supported Liquid Phase Catalysis (ChemCatChem 8/2022)

The Cover Feature shows a hexagonal boron nitride plane. On top of the plane are liquid diborontrioxide droplets, which catalyze the oxidative dehydrogenation of propane. In their Research Article, P. Schmatz-Engert et al. explain that these melt films can be seen as the active phase in the boron catalyzed oxidative dehydrogenation of propane to propylene. Via in situ XRD analysis the authors were able to document the transformation process of oxygen functionalized hexagonal boron nitride to a supported liquid phase. In the upcoming research field of selective alkane oxidativedehydrogenation these results offers new opportunities for an innovative catalyst design. More information can be found in the Research Article by P. Schmatz-Engert et al.

Oxygen‐Functionalized Boron Nitride for the Oxidative Dehydrogenation of Propane – The Case for Supported Liquid Phase Catalysis

AbstractBoron and boron containing materials have created a new class of catalysts for the highly selective conversion of light alkanes to building block olefins. Boron oxide species seem to play an essential role for the oxidative dehydrogenation of propane. For boron nitride they are created through an induction process under reaction conditions. It is still not obvious how different kinds of oxidative pre‐activation influences the observed activity and selectivity. Here we compare two different oxygen activation strategies of boron nitride, a classical activation by calcination at different temperatures and ball‐milling with varying rotation velocity. These treatments allow to control the amount of introduced boron oxide species from 0.2 to 17.5 wt.‐%, as quantified by alkalimetric titration. The catalytic experimental data together with the pre, post as well as in situ characterization, give insights how the catalyst's surface changes under reaction conditions. On this backdrop it can be deduced that molten boron oxide predominantly acts as catalyst under reaction conditions, and boron nitride as catalyst support.

Capturing spatially resolved kinetic data and coking of Ga-Pt supported catalytically active liquid metal solutions during propane dehydrogenation in situ.

Supported liquid phase catalysis has great potential to unify the advantages from both homogeneous and heterogeneous catalysis. Recently, we reported supported catalytically active liquid metal solutions (SCALMS) as a new class of liquid phase catalysts. SCALMS enable high temperature application due to the high thermal stability of liquid metals when compared to supported molten salts or ionic liquids. The highly dynamic liquid metal/gas interface of SCALMS allows for catalysis over single atoms of an active metal atom within a matrix of liquid gallium. In the present study, kinetic data is acquired along the catalyst bed in a compact profile reactor during propane dehydrogenation (PDH) over gallium-platinum SCALMS. The reactor design allows for the analysis of the temperature and gas phase composition along the catalyst bed with a high spatial resolution using a sampling capillary inside the reactor. The concentration profiles suggest enhanced deactivation of the catalyst at the end of the bed with a deactivation front moving from the end to the beginning of the catalyst bed over time on stream. Only minor amounts of side products, formed via cracking of propane, were identified, supporting previously reported high selectivity of SCALMS during alkane dehydrogenation. The acquired data is supported by in situ high-resolution thermogravimetry coupled with mass spectrometry to monitor the activity and coking behaviour of SCALMS during PDH. The results strongly suggest an enhanced formation of coke over Al2O3-supported SCALMS when compared to using SiO2 as the support material.

Supported Liquid Phase Catalysis as a Novel Concept for Oxidative Dehydrogenation of Ethane

Supported Liquid Phase Catalysis as a Novel Concept for Oxidative Dehydrogenation of Ethane

Supported Fluorous Phase Catalysis on PTFE, Fluoroalkylated Micro‐ and Meso‐porous Silica

AbstractNew perfluoroalkylated micro‐ and mesoporous silica, along with powdered Teflon, have been evaluated as solid supports for supported fluorous phase catalysis in a model reaction; the hydrogenation of styrene using a fluorous analogue of Wilkinson’s catalyst. Each support material showed catalytic activity and catalyst‐leaching behaviour related to its surface area and was consistent with supported liquid phase catalysis. However, catalyst decomposition on the silica supports resulted in substantial reductions in activity on catalyst recycle. In contrast, although activity and leaching levels on PTFE were poorer, the supported catalyst was recycled successfully.

ChemInform Abstract: Supported Liquid Phase Catalysis in Selective Oxidation

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Supported liquid phase catalysis in selective oxidation

The application of supported liquid-phase catalysis (SLPC) to selective oxidation examples is discussed to provide valuable alternatives to the purely homogeneous or heterogenous processes. Specific examples discussed are the Wacker type ethylene oxidation on heterogenous catalysts and the vinyl acetate production by ethylene acetoxylation. The potential industrial application of SLPC for these oxidations and the possible extensions of this technology to other oxidation processes are also discussed.

Solvent‐Anchored Supported Liquid Phase Catalysis: Polyoxometalate‐Catalyzed Oxidations

Solvent‐Anchored Supported Liquid Phase Catalysis: Polyoxometalate‐Catalyzed Oxidations

Supported liquid-phase catalysis: III. Experimental evaluation of the diffusion-reaction model

The theoretical model for transport and reaction in supported liquid-phase catalysis (SLPC) proposed in Part I (R. Datta and R. G. Rinker, J. Catal. 95, 181, 1985) was tested experimentally using two different homogeneously catalyzed model reactions. The hydrogenation of ethylene catalyzed by a RhCl(CO)(PPh 3) 2 solution and the isomerization of quadricyclene catalyzed by a Co(III)TPPCl solution were used to study the behavior of SLPC at low and high solubility, respectively. The experimental results were found to be in good quantitative agreement with the theoretical model for both cases.

Kinetics of quadricyclene-norbornadiene isomerization reaction for use in modeling supported liquid-phase catalysis

The isomerization kinetics of quadricyclene (tetracyclo[3.2.0.0 2,7.0 4,6]heptane) to norbornadiene (bicyclo[2.2.1]hepta-2,5-diene) was chosen as a reaction appropriate to the study of supported liquid-phase catalysis (SLPC). An infrared spectrophotometer, modified to permit measurement of reaction rates with half-lives of ~1 sec, was used to determine the intrinsic rate constant and its temperature dependence. These quantities are essential in evaluating SLPC systems.