Isomorphic MOFs functionalized by free-standing acylamide and organic groups serving as self-supported catalysts for the CO2 cycloaddition reaction

2016 ◽  
Vol 40 (3) ◽  
pp. 2904-2909 ◽  
Author(s):  
Lili Song ◽  
Chao Chen ◽  
Xiangbin Chen ◽  
Ning Zhang
Keyword(s):  
Catalytic Effect ◽  
Supported Catalysts ◽  
Cycloaddition Reaction ◽  
Free Standing ◽  
Catalytic Activities

MOFs exhibited different catalytic activities depending on the organic groups decorated on the pore walls, which displayed a synergetic catalytic effect.

scholarly journals Electrodeposition of palladium-dotted nickel nanowire networks as a robust self-supported methanol electrooxidation catalyst

2021 ◽  
Author(s):  
Tim Boettcher ◽  
Sasho Stojkovikj ◽  
Prashant Khadke ◽  
Ulrike Kunz ◽  
Matthew T. Mayer ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
High Mass ◽  
Potential Cycling ◽  
Free Standing ◽  
Term Stability ◽  
Long Term Stability ◽  
Mass Activity ◽  
Nickel Nanowire ◽  
Nanowire Networks

Abstract Mass activity and long-term stability are two major issues in current fuel cell catalyst designs. While supported catalysts normally suffer from poor long-term stability but show high mass activity, unsupported catalysts tend to perform better in the first point while showing deficits in the latter one. In this study, a facile synthesis route towards self-supported metallic electrocatalyst nanoarchitectures with both aspects in mind is outlined. This procedure consists of a palladium seeding step of ion track-etched polymer templates followed by a nickel electrodeposition and template dissolution. With this strategy, free-standing nickel nanowire networks which contain palladium nanoparticles only in their outer surface are obtained. These networks are tested in anodic half-cell measurements for demonstrating their capability of oxidising methanol in alkaline electrolytes. The results from the electrochemical experiments show that this new catalyst is more tolerant towards high methanol concentrations (up to $${5}\,\hbox{mol}\,\hbox{L}^{-1}$$ 5 mol L - 1 ) than a commercial carbon supported palladium nanoparticle catalyst and provides a much better long-term stability during potential cycling. Graphical Abstract

scholarly journals Synthesis of a Novel Series of Cu(I) Complexes Bearing Alkylated 1,3,5-Triaza-7-phosphaadamantane as Homogeneous and Carbon-Supported Catalysts for the Synthesis of 1- and 2-Substituted-1,2,3-triazoles

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2702
Author(s):  
Ivy L. Librando ◽  
Abdallah G. Mahmoud ◽  
Sónia A. C. Carabineiro ◽  
M. Fátima C. Guedes da Silva ◽  
Carlos F. G. C. Geraldes ◽  
...  
Keyword(s):  
Aqueous Medium ◽  
Sodium Azide ◽  
Supported Catalysts ◽  
Cycloaddition Reaction ◽  
Water Soluble ◽  
Terminal Alkynes ◽  
One Pot ◽  
Catalytic Systems ◽  
Immobilized Catalyst ◽  
High Yields

The N-alkylation of 1,3,5-triaza-7-phosphaadamantane (PTA) with ortho-, meta- and para-substituted nitrobenzyl bromide under mild conditions afforded three hydrophilic PTA ammonium salts, which were used to obtain a new set of seven water-soluble copper(I) complexes. The new compounds were fully characterized and their catalytic activity was investigated for the low power microwave assisted one-pot azide–alkyne cycloaddition reaction in homogeneous aqueous medium to obtain disubstituted 1,2,3-triazoles. The most active catalysts were immobilized on activated carbon (AC), multi-walled carbon nanotubes (CNT), as well as surface functionalized AC and CNT, with the most efficient support being the CNT treated with nitric acid and NaOH. In the presence of the immobilized catalyst, several 1,4-disubstituted-1,2,3-triazoles were obtained from the reaction of terminal alkynes, organic halides and sodium azide in moderate yields up to 80%. Furthermore, the catalyzed reaction of terminal alkynes, formaldehyde and sodium azide afforded 2-hydroxymethyl-2H-1,2,3-triazoles in high yields up to 99%. The immobilized catalyst can be recovered and recycled through simple workup steps and reused up to five consecutive cycles without a marked loss in activity. The described catalytic systems proceed with a broad substrate scope, under microwave irradiation in aqueous medium and according to “click rules”.

scholarly journals Green Pathway in Utilizing CO2 via Cycloaddition Reaction with Epoxide—A Mini Review

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 548 ◽  
Author(s):  
Kunlanan Kiatkittipong ◽  
Muhammad Amirul Amin Mohamad Shukri ◽  
Worapon Kiatkittipong ◽  
Jun Wei Lim ◽  
Pau Loke Show ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
Metal Organic Framework ◽  
Sustainable Use ◽  
Cycloaddition Reaction ◽  
Cyclic Carbonate ◽  
Organic Salt ◽  
Catalytic Systems ◽  
Carbonate Production ◽  
Use Of Resources ◽  
Salen Complexes

Carbon dioxide (CO2) has been anticipated as an ideal carbon building block for organic synthesis due to the noble properties of CO2, which are abundant renewable carbon feedstock, non-toxic nature, and contributing to a more sustainable use of resources. Several green and proficient routes have been established for chemical CO2 fixation. Among the prominent routes, this review epitomizes the reactions involving cycloaddition of epoxides with CO2 in producing cyclic carbonate. Cyclic carbonate has been widely used as a polar aprotic solvent, as an electrolyte in Li-ion batteries, and as precursors for various forms of chemical synthesis such as polycarbonates and polyurethanes. This review provides an overview in terms of the reaction mechanistic pathway and recent advances in the development of several classes of catalysts, including homogeneous organocatalysts (e.g., organic salt, ionic liquid, deep eutectic solvents), organometallic (e.g., mono-, bi-, and tri-metal salen complexes and non-salen complexes) and heterogeneous supported catalysts, and metal organic framework (MOF). Selection of effective catalysts for various epoxide substrates is very important in determining the cycloaddition operating condition. Under their catalytic systems, all classes of these catalysts, with regard to recent developments, can exhibit CO2 cycloaddition of terminal epoxide substrates at ambient temperatures and low CO2 pressure. Although highly desired conversion can be achieved for internal epoxide substrates, higher temperature and pressure are normally required. This includes fatty acid-derived terminal epoxides for oleochemical carbonate production. The production of fully renewable resources by employment of bio-based epoxy with biorefinery concept and potential enhancement of cycloaddition reactions are pointed out as well.

Support Effect in Carbon Oxide(s) Hydrogenation on Cu-Cr Supported Catalysts

1993 ◽  
Vol 58 (4) ◽  
pp. 791-797
Author(s):  
Zahia Rassoul ◽  
Joël Barrault ◽  
Mohamed M. Bettahar
Keyword(s):  
Catalytic Properties ◽  
Supported Catalysts ◽  
Strong Support ◽  
Supported Catalyst ◽  
Carbon Oxide ◽  
Support Effect ◽  
Catalytic Activities ◽  
And Storage ◽  
Adsorptive Properties ◽  
Reduced State

Reducibility, adsorptive properties and catalytic properties of Cu-Cr supported on TiO2, ZnO and Al2O3 were studied in carbon oxide(s) hydrogenation. ZnO is the best retardant for the reduction of copper, stabilizing more strongly Cu+ species and retaining great amounts of H2 during the reduction of the calcined precursors. A strong support effect is observed for the CO2/H2 reaction and good correlations are established between catalytic activities, Cu+ species present in the reduced state and H2 adsorption and storage. ZnO is the most active support but not the most selective one for this reaction. The support effect is not so important for the CO/H2 reaction, but ZnO supported catalyst is again the most active and also the most selective.

scholarly journals Enhanced Photocatalytic Degradation of Rhodamine B Using C/Fe Co-Doped Titanium Dioxide Coated on Activated Carbon

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Thuy Le Thi Thanh ◽  
Lan Nguyen Thi ◽  
Trinh Tran Dinh ◽  
Noi Nguyen Van
Keyword(s):  
Titanium Dioxide ◽  
Activated Carbon ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Supported Catalysts ◽  
Sol Gel ◽  
Adsorption Effect ◽  
Catalytic Activities ◽  
Doped Titanium Dioxide ◽  
Co Doped

Carbon and iron co-doped titanium dioxide catalyst coated on activated carbon (Fe-C-TiO2/AC) was successfully synthesized using the sol-gel method, followed by hydrothermal treatment. Commercial activated carbon was treated by HNO3 prior to being coated by the as-synthesized catalyst. The composite was characterized by XPS, XRD, UV-Vis spectrophotometry, IR, TEM, HR-TEM, and BET. The performance of the supported catalysts was evaluated in the degradation of rhodamine B (RhB) in the solution under visible-light irradiation. The results showed that, with the appropriate amount of activated carbon, prepared Fe-C-TiO2/AC catalysts exhibited higher catalytic activities and Fe-C-TiO2/AC system showed the best performance. The photocatalytic degradation efficiency of Fe-C-TiO2/AC was enhanced due to the synergistic effect between AC (adsorption effect) and Fe-C-TiO2 (photocatalysis effect). This facilitated the photocatalytic degradation of RhB by Fe-C-TiO2.

scholarly journals Cerium Salts: An Efficient Curing Catalyst for Benzoxazine Based Coatings

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 415 ◽  
Author(s):  
Tao Zhang ◽  
Leïla Bonnaud ◽  
Jean-Marie Raquez ◽  
Marc Poorteman ◽  
Marjorie Olivier ◽  
...  
Keyword(s):  
Glass Transition ◽  
Ring Opening ◽  
Catalytic Effect ◽  
Ring Opening Polymerization ◽  
Curing Temperature ◽  
Energy Dispersive ◽  
Glass Transition Temperatures ◽  
X Ray ◽  
Catalytic Activities ◽  
Ft Ir

The effect of three different cerium salts (Ce(NO3)3·6H2O, CeCl3·7H2O and Ce(OOCCH3)3·5H2O) on the ring-opening polymerization (ROP) of a model diamine-based benzoxazine (4EP-pPDA) was investigated. With the incorporation of the cerium salts, the curing temperature of 4EP-pPDA is reduced substantially, and the glass transition temperatures of the resulting networks are increased significantly. The three cerium salts exhibit different catalytic activities, which were analyzed by FT-IR, NMR, and energy-dispersive X-ray (EDX). Ce(NO3)3·6H2O was found to exhibit the best catalytic effect, which seems to be related to its better dispersibility within 4EP-pPDA benzoxazine precursors.

Catalytic Decomposition of N2O ON ZrO2 and Co/Ni/ZrO2 Systems

1994 ◽  
Vol 344 ◽  
Author(s):  
H. C. Zeng ◽  
J. Lin ◽  
W. K. Teo ◽  
J. Wu ◽  
K. L. Tan
Keyword(s):  
Partial Pressure ◽  
Catalytic Effect ◽  
Supported Catalysts ◽  
Catalytic Decomposition ◽  
Surface Region ◽  
Threshold Concentration ◽  
Decomposition Mechanism ◽  
First Order ◽  
Ni Content ◽  
Xps Study

AbstractMonoclinic ZrO2 and its supported catalysts Co/Ni/ZrO2 for catalytic decomposition of N2O have been studied with FTIR, EDAX, XPS, and the evaluation of activity of the catalysts. It is found that monoclinic ZrO2 alone has the catalytic effect for N2O decomposition although the gas decomposes on Co/Ni/ZrO2 more efficiently. The XPS study shows that only Co exists in the surface region of ZrO2. In evaluation experiments, it is found that when Co/Ni exceeds a threshold concentration, the conversion of N2O is no longer accelerated with the increase of Co/Ni content. The gas decomposition on Co/Ni/ZrO2 can be described as first order with respect to partial pressure of N2O. No nitrogen N(ls) photoelectrons were detected for the catalysts after N2O decomposition. Surface reactions on ZrO2 and Co/Ni/ZrO2, including the behaviour of retained carbon (Cls) and N2O decomposition mechanism, will also be addressed.

Coherent electron nanodiffraction from clean silver nano particles in a UHV STEM

1993 ◽  
Vol 51 ◽  
pp. 1058-1059
Author(s):  
J. Liu ◽  
M. Pan ◽  
G. E. Spinnler
Keyword(s):  
Supported Catalysts ◽  
Imaging Techniques ◽  
Nano Particles ◽  
Metal Particles ◽  
Shape Structure ◽  
Dynamical Simulations ◽  
Small Metal Particles ◽  
Extract Information

Small metal particles have peculiar chemical and physical properties as compared to bulk materials. They are especially important in catalysis since metal particles are common constituents of supported catalysts. The structural characterization of small particles is of primary importance for the understanding of structure-catalytic activity relationships. The shape and size of metal particles larger than approximately 5 nm in diameter can be determined by several imaging techniques. It is difficult, however, to deduce the shape of smaller metal particles. Coherent electron nanodiffraction (CEND) patterns from nano particles contain information about the particle size, shape, structure and defects etc. As part of an on-going program of STEM characterization of supported catalysts we report some preliminary results of CEND study of Ag nano particles, deposited in situ in a UHV STEM instrument, and compare the experimental results with full dynamical simulations in order to extract information about the shape of Ag nano particles.

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