Multifunctional Heterogeneous Catalysts: SBA-15-Containing Primary Amines and Sulfonic Acids

2006 ◽  
Vol 45 (38) ◽  
pp. 6332-6335 ◽  
Author(s):  
Ryan K. Zeidan ◽  
Son-Jong Hwang ◽  
Mark E. Davis
Keyword(s):  
Heterogeneous Catalysts ◽  
Primary Amines ◽  
Sulfonic Acids

Multifunctional Heterogeneous Catalysts: SBA-15-Containing Primary Amines and Sulfonic Acids

2006 ◽  
Vol 118 (38) ◽  
pp. 6480-6483 ◽  
Author(s):  
Ryan K. Zeidan ◽  
Son-Jong Hwang ◽  
Mark E. Davis
Keyword(s):  
Heterogeneous Catalysts ◽  
Primary Amines ◽  
Sulfonic Acids

Mesoporous Sulfonic Acids as Selective Heterogeneous Catalysts for the Synthesis of Monoglycerides

1999 ◽  
Vol 182 (1) ◽  
pp. 156-164 ◽  
Author(s):  
Wim D. Bossaert ◽  
Dirk E. De Vos ◽  
Wim M. Van Rhijn ◽  
Joren Bullen ◽  
Piet J. Grobet ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Sulfonic Acids

Reactivity of triformylmethane. I. Reactions of triformylmethane with selected types of amino compounds

1991 ◽  
Vol 56 (5) ◽  
pp. 1019-1031 ◽  
Author(s):  
Zdeněk Arnold ◽  
Miloš Buděšínský ◽  
Magdalena Pánková
Keyword(s):  
Lewis Acids ◽  
Secondary Amines ◽  
Primary Amines ◽  
Carbamic Acid ◽  
Sulfonic Acids ◽  
Primary Products ◽  
Amino Compounds ◽  
Related Compounds

Reactions of triformylmethane with various types of amino compounds were investigated. Besides with ammonia, triformylmethane reacts spontaneously with primary amines, aminoacids and their esters, urea and related compounds including carbamic acid derivatives. Reactions with amides of carboxylic and sulfonic acids require catalysis with Lewis acids. Primary products are aminomethylenemalonaldehyde derivatives IIIa-IIIv. Reactions of triformylmethane with excess of selected primary amines and two secondary amines (dimethylamine and morpholine) were also studied.

scholarly journals Sulfonic Acids Supported on UiO-66 as Heterogeneous Catalysts for the Esterification of Fatty Acids for Biodiesel Production

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1271
Author(s):  
Wei Liu ◽  
Fang Wang ◽  
Pengcheng Meng ◽  
Shuang-Quan Zang
Keyword(s):  
Fatty Acids ◽  
Heterogeneous Catalysts ◽  
Methanesulfonic Acid ◽  
Biodiesel Production ◽  
Solid Catalyst ◽  
Acid Catalysts ◽  
Sulfonic Acids ◽  
Catalyst Reusability ◽  
Esterification Reactions ◽  
Adsorption Desorption

Zr-MOF (UiO-66) catalysts PTSA/UiO-66 and MSA/UiO-66 bearing supported sulfonic acids (p-toluenesulfonic acid and methanesulfonic acid, respectively) were prepared through a simple impregnation approach. The UiO-66-supported sulfonic acid catalysts were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, fourier transform infrared spectroscopy (FT-IR) and elemental analysis. The prepared heterogeneous acid catalysts had excellent stability since their crystalline structure was not changed compared with that of the original UiO-66. Zr-MOF MSA/UiO-66 and PTSA/UiO-66 were next successfully used as heterogeneous acid catalysts for the esterification of biomass-derived fatty acids (e.g., palmitic acid, oleic acid) with various alcohols (e.g., methanol, n-butanol). The results demonstrated that both of them had high activity and excellent reusability (more than nine successive cycles) in esterification reactions. Alcohols with higher polarity (e.g., methanol) affected the solid catalyst reusability slightly, while alcohols with moderate or lower polarity (e.g., n-butanol, n-decanol) had no influence. Thus, these developed sulfonic acids-supported metal-organic frameworks (UiO-66) have the potential for use in biodiesel production with excellent reusability.

scholarly journals Silica-supported Fe/Fe–O nanoparticles for the catalytic hydrogenation of nitriles to amines in the presence of aluminium additives

2021 ◽  
Author(s):  
Vishwas G. Chandrashekhar ◽  
Thirusangumurugan Senthamarai ◽  
Ravishankar G. Kadam ◽  
Ondřej Malina ◽  
Josef Kašlík ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Life Sciences ◽  
Industrial Process ◽  
Silica Matrix ◽  
Primary Amines ◽  
Shell Nanoparticles ◽  
Functionally Diverse ◽  
Core Shell Nanoparticles ◽  
Aromatic Heterocyclic ◽  
Hydrogenation Of Nitriles

AbstractThe hydrogenation of nitriles to amines represents an important and frequently used industrial process due to the broad applicability of the resulting products in chemistry and life sciences. Despite the existing portfolio of catalysts reported for the hydrogenation of nitriles, the development of iron-based heterogeneous catalysts for this process is still a challenge. Here, we show that the impregnation and pyrolysis of iron(II) acetate on commercial silica produces a reusable Fe/Fe–O@SiO2 catalyst with a well-defined structure comprising the fayalite phase at the Si–Fe interface and α-Fe nanoparticles, covered by an ultrathin amorphous iron(III) oxide layer, growing from the silica matrix. These Fe/Fe–O core–shell nanoparticles, in the presence of catalytic amounts of aluminium additives, promote the hydrogenation of all kinds of nitriles, including structurally challenging and functionally diverse aromatic, heterocyclic, aliphatic and fatty nitriles, to produce primary amines under scalable and industrially viable conditions.

ChemInform Abstract: Friedel-Crafts Acylation Reaction with Anhydrides: Silica-Supported Sulfonic Acids as Green and Efficients Heterogeneous Catalysts

ChemInform ◽  
2012 ◽  
Vol 43 (23) ◽  
pp. no-no
Author(s):  
Calogero G. Piscopo ◽  
Andrea Adorni ◽  
Raimondo Maggi ◽  
Giovanni Sartori
Keyword(s):  
Heterogeneous Catalysts ◽  
Acylation Reaction ◽  
Sulfonic Acids

What catalysis needs from the electron microscopist

1988 ◽  
Vol 46 ◽  
pp. 694-695
Author(s):  
Alexis T. Bell
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Catalyst Deactivation ◽  
Surface Composition ◽  
Internal Surface ◽  
Active Phase ◽  
Atomic Scale ◽  
Metal Catalyst ◽  
Internal Surface Area ◽  
Porous Support

Heterogeneous catalysts, used in industry for the production of fuels and chemicals, are microporous solids characterized by a high internal surface area. The catalyticly active sites may occur at the surface of the bulk solid or of small crystallites deposited on a porous support. An example of the former case would be a zeolite, and of the latter, a supported metal catalyst. Since the activity and selectivity of a catalyst are known to be a function of surface composition and structure, it is highly desirable to characterize catalyst surfaces with atomic scale resolution. Where the active phase is dispersed on a support, it is also important to know the dispersion of the deposited phase, as well as its structural and compositional uniformity, the latter characteristics being particularly important in the case of multicomponent catalysts. Knowledge of the pore size and shape is also important, since these can influence the transport of reactants and products through a catalyst and the dynamics of catalyst deactivation.

Electron holography of catalysts

1995 ◽  
Vol 53 ◽  
pp. 416-417
Author(s):  
A. K. Datye ◽  
D. S. Kalakkad ◽  
L. F. Allard ◽  
E. Völkl
Keyword(s):  
Heterogeneous Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Atomic Scale ◽  
Nano Particles ◽  
Phase Image ◽  
Electron Holography ◽  
Specimen Thickness ◽  
Phase Information ◽  
Particle Structure

The active phase in heterogeneous catalysts consists of nanometer-sized metal or oxide particles dispersed within the tortuous pore structure of a high surface area matrix. Such catalysts are extensively used for controlling emissions from automobile exhausts or in industrial processes such as the refining of crude oil to produce gasoline. The morphology of these nano-particles is of great interest to catalytic chemists since it affects the activity and selectivity for a class of reactions known as structure-sensitive reactions. In this paper, we describe some of the challenges in the study of heterogeneous catalysts, and provide examples of how electron holography can help in extracting details of particle structure and morphology on an atomic scale.Conventional high-resolution TEM imaging methods permit the image intensity to be recorded, but the phase information in the complex image wave is lost. However, it is the phase information which is sensitive at the atomic scale to changes in specimen thickness and composition, and thus analysis of the phase image can yield important information on morphological details at the nanometer level.

Quantitative nano-characterization of heterogeneous catalysts

1995 ◽  
Vol 53 ◽  
pp. 398-399
Author(s):  
P.A. Crozier ◽  
M. Pan
Keyword(s):  
Heterogeneous Catalysts ◽  
Low Dose ◽  
Imaging Techniques ◽  
Structural Features ◽  
Catalyst Characterization ◽  
New Developments ◽  
Double Phase ◽  
Phase Systems ◽  
Dose Imaging

Heterogeneous catalysts can be of varying complexity ranging from single or double phase systems to complicated mixtures of metals and oxides with additives to help promote chemical reactions, extend the life of the catalysts, prevent poisoning etc. Although catalysis occurs on the surface of most systems, detailed descriptions of the microstructure and chemistry of catalysts can be helpful for developing an understanding of the mechanism by which a catalyst facilitates a reaction. Recent years have seen continued development and improvement of various TEM, STEM and AEM techniques for yielding information on the structure and chemistry of catalysts on the nanometer scale. Here we review some quantitative approaches to catalyst characterization that have resulted from new developments in instrumentation.HREM has been used to examine structural features of catalysts often by employing profile imaging techniques to study atomic details on the surface. Digital recording techniques employing slow-scan CCD cameras have facilitated the use of low-dose imaging in zeolite structure analysis and electron crystallography. Fig. la shows a low-dose image from SSZ-33 zeolite revealing the presence of a stacking fault.

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