scholarly journals Effects of Coordination Ability of Nitrogen-Containing Carboxylic Acid Ligands on Nieuwland Catalyst

Catalysts ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 337 ◽  
Author(s):  
Yanhe You ◽  
Juan Luo ◽  
Jianwei Xie ◽  
Jinli Zhang ◽  
Bin Dai
Keyword(s):  
Catalytic Activity ◽  
Carboxylic Acid ◽  
Iminodiacetic Acid ◽  
Catalyst System ◽  
Excellent Performance ◽  
Coordination Ability ◽  
Cu Ions

This article investigated the effect of three nitrogen-containing carboxylic acid ligands for the Nieuwland catalyst system. The catalyst system containing 4.5% N-(2-acetamido) iminodiacetic acid exhibited improved catalytic activity with excellent performance. The yield of monovinylacetylene (MVA) was maintained at 36.7% after 24 h, which was increased by 17.1% relative to the Nieuwland catalyst system. Based on a variety of analyses on the crystals precipitated from the catalyst solutions, it can be inferred that the outstanding performance and lifetime of the catalysts were related to the abilities of these ligands to form strong coordination with Cu+ ions and stabilize them.

A metal–organic framework with in situ generated low-coordinate binuclear Cu(i) units as a highly effective catalyst for photodriven hydrogen production

2020 ◽  
Vol 56 (49) ◽  
pp. 6700-6703
Author(s):  
Ning-Yu Huang ◽  
Hai He ◽  
Hao Li ◽  
Pei-Qin Liao ◽  
Xiao-Ming Chen
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Production ◽  
Synergistic Effect ◽  
Metal Organic Framework ◽  
High Catalytic Activity ◽  
Binuclear Copper ◽  
Metal Organic ◽  
Cu Ions ◽  
Organic Framework

Here, we report a metal–organic framework featuring a binuclear copper unit, showing extraordinarily high catalytic activity (102.8 mmol g−1 h−1) for photodriven H2 generation, which is attributed to the synergistic effect between the two Cu ions.

Niobium(v) chloride and imidazolium bromides as efficient dual catalyst systems for the cycloaddition of carbon dioxide and propylene oxide

2014 ◽  
Vol 4 (6) ◽  
pp. 1638-1643 ◽  
Author(s):  
Michael E. Wilhelm ◽  
Michael H. Anthofer ◽  
Robert M. Reich ◽  
Valerio D'Elia ◽  
Jean-Marie Basset ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Activity ◽  
Propylene Oxide ◽  
Catalyst System ◽  
Cyclic Carbonates ◽  
Imidazolium Salt ◽  
Catalyst Systems

Imidazolium bromides combined with niobium(v) choride were used as catalyst system for the reaction of CO2 with epoxides to cyclic carbonates. The variation of the cation structure strongly affects the properties of the imidazolium salt and therefore the catalytic activity.

Oxidation of 1,2-Propanediol to Carboxylic Acid Over Hydroxyapatite Nanorod-Supported Metallic Cu0 Nanoparticles

2020 ◽  
Vol 20 (3) ◽  
pp. 1723-1731 ◽  
Author(s):  
Lang Qiu ◽  
Hengbo Yin ◽  
Aili Wang ◽  
Lingqin Shen ◽  
Wei Tao
Keyword(s):  
Catalytic Activity ◽  
Crystal Growth ◽  
Carboxylic Acid ◽  
Reaction Temperature ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Chemical Reduction Method ◽  
Gaseous Oxygen ◽  
Nanoparticle Catalysts

Hydroxyapatite nanorod-supported metallic Cu0 nanoparticle catalysts (Cux/HAP) were prepared by the wetness chemical reduction method. The metallic Cu0 nanoparticles were well dispersed on the surfaces of the HAP nanorods. The alkaline HAP nanorods inhibited the crystal growth of the metallic Cu0 nanoparticles. The HAP nanorods also retarded the oxidation of the metallic Cu0 nanoparticles. The Cux/HAP catalyst exhibited a higher catalytic activity for the oxidation of 1,2-propanediol with gaseous oxygen to lactic, acetic, and formic acids with the total selectivity of 70.3% even at a lower reaction temperature of 140 °C. The total selectivity of lactic, acetic, and formic acids reached 93.1% at a mild reaction temperature of 180 °C. However, the sole monometallic Cu0 nanoparticles or HAP nanorods had no catalytic activity for the oxidation of 1,2-propanediol. The metallic Cu0 nanoparticles and alkaline HAP nanorods in the Cux/HAP catalyst synergistically catalyzed the oxidation of 1,2-propanediol to carboxylic acid.

scholarly journals An efficient Pd–NHC catalyst system in situ generated from Na2PdCl4 and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

2017 ◽  
Vol 13 ◽  
pp. 1735-1744 ◽  
Author(s):  
Nan Sun ◽  
Meng Chen ◽  
Liqun Jin ◽  
Wei Zhao ◽  
Baoxiang Hu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Imidazole Ring ◽  
Catalyst System ◽  
Water Soluble ◽  
Imidazolium Salts ◽  
Heck Reactions ◽  
Imidazolium Salt ◽  
Simple Method ◽  
Wide Range

Three PEG-functionalized imidazolium salts L1–L3 were designed and prepared from commercially available materials via a simple method. Their corresponding water soluble Pd–NHC catalysts, in situ generated from the imidazolium salts L1–L3 and Na2PdCl4 in water, showed impressive catalytic activity for aqueous Mizoroki–Heck reactions. The kinetic study revealed that the Pd catalyst derived from the imidazolium salt L1, bearing a pyridine-2-methyl substituent at the N3 atom of the imidazole ring, showed the best catalytic activity. Under the optimal conditions, a wide range of substituted alkenes were achieved in good to excellent yields from various aryl bromides and alkenes with the catalyst TON of up to 10,000.

Application of [Ru((R)-BINAP)(MeCN)(1-3:5,6-η-C8H11)](BF4) as a catalyst precursor for enantioselective hydrogenations

1998 ◽  
Vol 76 (10) ◽  
pp. 1447-1456 ◽  
Author(s):  
Christopher JA Daley ◽  
Jason A Wiles ◽  
Steven H Bergens
Keyword(s):  
Carboxylic Acid ◽  
Type Systems ◽  
Enantioselective Hydrogenation ◽  
Catalyst System ◽  
Structural Features ◽  
Catalyst Precursor ◽  
Unsaturated Carboxylic Acid ◽  
Tiglic Acid ◽  
Protic Solvents ◽  
Acid Methyl

A catalyst system employing [Ru((R)-BINAP)(MeCN)(1-3:5,6-η-C8H11)](BF4) as catalyst precursor was evaluated using the enantioselective hydrogenations of tiglic acid, α-acetamidocinnamic acid, itaconic acid, methyl tiglate, dimethyl itaconate, geraniol, ethyl acetoacetate, and dimethyl oxaloacetate as a series of typical substrates. Acetone and MeOH were used as model aprotic and protic solvents, respectively. The hydrogenation of substrates containing an α, β-unsaturated carboxylic acid functionality required stoichiometric quantities of NEt3 to occur at reasonable rates in acetone solution, while in MeOH solution it did not. The enantioselectivities were typically higher in acetone than in MeOH. This catalyst system is among the more enantioselective ruthenium-BINAP type systems reported for the catalytic hydrogenation of substrates containing an α, β-unsaturated acid or ester functionality. The enantioselectivities for the hydrogenation of ketones ranged from poor (15%) to moderate (74%). 1,4-Dicarboxylate substrates with the prochiral olefin or ketone at the 2-position were all hydrogenated in good to high ee with the same enantioface selectivity both with our system and other catalysts reported in the literature. This raised the possibility that these substrates were hydrogenated through intermediates with similar structural features. Key words: ruthenium, BINAP, enantioselective, hydrogenation, catalysis.

Three metal complexes derived from 3-methyl-1H-pyrazole-4-carboxylic acid: synthesis, crystal structures, luminescence and electrocatalytic properties

RSC Advances ◽  
2016 ◽  
Vol 6 (57) ◽  
pp. 52040-52047 ◽  
Author(s):  
Jing Liu ◽  
Mei-Ling Cheng ◽  
Li-Li Yu ◽  
Sheng-Chun Chen ◽  
Yong-Liang Shao ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Carboxylic Acid ◽  
Metal Complexes ◽  
Crystal Structures ◽  
Acid Synthesis ◽  
Bifunctional Catalyst ◽  
Electrocatalytic Properties ◽  
Catalyst Complex

[Cd(HMPCA)2(H2O)4] (1), [Co(H2MPCA)2(DMF)2(H2O)2]Cl2(2), and [Cd3Cl2(HMPCA)4(H2O)2]·2H2O (3) have been synthesized. As a bifunctional catalyst, complex2exhibited excellent catalytic activity for OER and certain catalytic activity for ORR.

scholarly journals Catalytic Conversion of Cellulose to 5-hydroxymethylfurfural (5-HMF) Over Nano SO42--ZrO2 /MCM-41 Catalysts

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Pham Tung Son ◽  
Le Ha Giang ◽  
Nguyen Ba Manh ◽  
Pham Thi Thu Trang ◽  
Vu Quang Loi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
High Selectivity ◽  
Sol Gel ◽  
Catalyst System ◽  
Hydroxymethyl Furfural ◽  
Structure And Morphology ◽  
Highly Dispersed ◽  
Ft Ir ◽  
Mcm 41 ◽  
Medium Acidity

A zirconium catalyst system supported on MCM-41 (S-Z) with various weight components (4-20 wt.%) Was synthesized by the sol-gel method. Structure and Morphology Catalysts were characterized by X-RD, TEM, BET, FT-IR and TPD-NH3 methods. In this catalyst, ZrO2 is highly dispersed on the surface of MCM-41 capillaries. Catalytic activity and selectivity were evaluated by the effectiveness of mild hydrothermal decomposition of cellulose to 5-hydroxymethyl furfural (5-HMF). The results show that a catalyst with medium acidity exhibits a high selectivity of 5-HMF. Keywords: S-Zr/MCM-41 materials, sol-gel methods, cellulose, 5-HMF.

scholarly journals Single-walled carbon nanotube supported Pt-Ru bimetallic superb nanocatalyst for the hydrogen generation from the methanolysis of methylamine-borane at mild conditions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Eda Gokirmak Sogut ◽  
Hilal Acidereli ◽  
Esra Kuyuldar ◽  
Yasar Karatas ◽  
Mehmet Gulcan ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Carbon Nanotube ◽  
Hydrogen Generation ◽  
Catalyst System ◽  
Metal Nanoparticle ◽  
High Catalytic Activity ◽  
Ambient Conditions ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Different Temperatures

Abstract Several metal nanoparticle based catalysts have been synthesized for catalyzing the hydrogen production process by hydrolysis of methylamine-borane (MeAB). However, there was only one study that catalyzes the producing of hydrogenvia the methanolysis of MeAB, and it was carried out by our research group. For this reason, in this work, a new catalyst system entitled by single-walled carbon nanotube (SWCNT) supported bimetallic platinum-ruthenium nanoparticles were developed and called as PtRu@SWCNT. These NPs were characterized by several techniques (XRD, XPS, Raman, and TEM), and they were performed for the methanolysis of MeAB with high catalytic activity. The prepared PtRu@SWCNT NPs were also tested in the methanolysis of MeAB at different parameters including different temperatures, catalyst and substrate concentrations, and reusability performance. Experimental results revealed that the new PtRu@SWCNT NPs had excellent catalytic activity and reusability for removing of hydrogen from the methanolysis of MeAB at ambient conditions. According to the obtained data, the turnover frequency is 136.25 mole H2/mole PtRu × min, and the activation energy (Ea) is 17.29 kJ/mole. More than 99% of conversion was observed at room temperature.

Sign in / Sign up

Export Citation Format

Share Document