Synthesis, characteristics and catalytic activity of water-soluble [Pd(lysine·HCl)(Cl)2] complex as hydrogenation catalyst

2007 ◽  
Vol 265 (1-2) ◽  
pp. 258-267 ◽  
Author(s):  
Yu-Zhi Hao ◽  
Zuo-Xi Li ◽  
Jin-Lei Tian
Keyword(s):  
Catalytic Activity ◽  
Water Soluble ◽  
Hydrogenation Catalyst

scholarly journals Catalytic Degradation of Chitosan by Supported Heteropoly Acids in Heterogeneous Systems

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1078
Author(s):  
Hang Zhang ◽  
Zhipeng Ma ◽  
Yunpeng Min ◽  
Huiru Wang ◽  
Ru Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Molecular Weight ◽  
Catalytic Activity ◽  
Activated Carbon ◽  
Reaction Time ◽  
High Molecular Weight ◽  
Reaction Temperature ◽  
Water Soluble ◽  
High Catalytic Activity ◽  
High Molecular Weight Chitosan

Several kinds of composite materials with phosphotungstic acid (PTA) as the catalyst were prepared with activated carbon as support, and their structures were characterized. According to the Box–Behnken central combination principle, the mathematical model of the heterogeneous system is established. Based on the single-factor experiments, the reaction temperature, the reaction time, the amount of hydrogen peroxide and the loading capacity of PTA were selected as the influencing factors to study the catalyzed oxidation of hydrogen peroxide and degradation of high molecular weight chitosan. The results of IR showed that the catalyst had a Keggin structure. The results of the mercury intrusion test showed that the pore structure of the supported PTA catalyst did not change significantly, and with the increase of PTA loading, the porosity and pore volume decreased regularly, which indicated that PTA molecules had been absorbed and filled into the pore of activated carbon. The results of Response Surface Design (RSD) showed that the optimum reaction conditions of supported PTA catalysts for oxidative degradation of high molecular weight chitosan by hydrogen peroxide were as follows: reaction temperature was 70 ℃, reaction time was 3.0 h, the ratio of hydrogen peroxide to chitosan was 2.4 and the catalyst loading was 30%. Under these conditions, the yield and molecular weight of water-soluble chitosan were 62.8% and 1290 Da, respectively. The supported PTA catalyst maintained high catalytic activity after three reuses, which indicated that the supported PTA catalyst had excellent catalytic activity and stable performance compared with the PTA catalyst.

Novel Co(II) phthalocyanines of extended periphery and their water-soluble derivatives. Synthesis, spectral properties and catalytic activity

2017 ◽  
Vol 1149 ◽  
pp. 17-26 ◽  
Author(s):  
Anna Filippova ◽  
Artur Vashurin ◽  
Serafima Znoyko ◽  
Ilya Kuzmin ◽  
Mikhail Razumov ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Spectral Properties ◽  
Water Soluble

Synthesis of a Water-Soluble Ruthenium Complex and Its Catalytic Activity for Acceptorless Alcohol Dehydrogenation in Aqueous Medium

Synlett ◽  
2018 ◽  
Vol 29 (12) ◽  
pp. 1644-1648 ◽  
Author(s):  
Senthilkumar Muthaiah ◽  
Anita Bhatia
Keyword(s):  
Catalytic Activity ◽  
Aqueous Medium ◽  
Ruthenium Complex ◽  
Water Soluble ◽  
Catalytic Cycle ◽  
Secondary Alcohols ◽  
Atom Economy ◽  
Hydrogen Acceptor ◽  
Alcohol Dehydrogenation ◽  
Acceptorless Alcohol Dehydrogenation

The synthesis of a ruthenium complex bearing a PN-chelating ligand is described. The complex, in the presence of KOH, enabled the synthesis of ketones from secondary alcohols in the absence of a hydrogen acceptor in aqueous medium. This synthetic protocol, which uses water as the medium, is green and has a high atom economy as it avoids the use of an acceptor and produces hydrogen as the sole ­byproduct. Mechanistic investigations revealed that the catalytic cycle involves a phosphine dissociative pathway.

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.

Catalytic Oxidation of 2-Mercaptoethanol by Cationic Water-soluble Phthalocyaninatocobalt(II) Complexes

1997 ◽  
Vol 01 (04) ◽  
pp. 309-313 ◽  
Author(s):  
MUTSUMI KIMURA ◽  
YUJI YAMAGUCHI ◽  
TOSHIKI KOYAMA ◽  
KENJI HANABUSA ◽  
HIROFUSA SHIRAI
Keyword(s):  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Absorption Spectra ◽  
Positive Charge ◽  
Alkyl Chain ◽  
Solvent Polarity ◽  
Water Soluble ◽  
Uv Absorption Spectra ◽  
Alkyl Chains ◽  
The Stability

The cationic amphiphilic cobalt(II) phthalocyanines have been prepared, and are characterized by UV-absorption spectra in water and organic solvents and in their mixtures. The monomer–dimer transformation equilibrium was affected by solvent polarity and the length of the alkyl chains in the amphiphilic parts. All complexes are efficient catalysts for the oxidation of 2-mercaptoethanol in the presence of dioxygen. The positive charge around the complex increases the acceleration of the dissociation of 2-mercaptoethanol under neutral pH. The catalytic activity is affected by the length of the alkyl chain; consequently the stability of aggregation between cobalt(II) phthalocyanines, as catalysts for the oxidation of 2-mercaptoethanol, can be changed.

The Rational Design and Synthesis of Water-Soluble Thiourea Ligands for Recoverable Pd-Catalyzed Aerobic Aqueous Suzuki–Miyaura Reactions at Room Temperature

Synthesis ◽  
2018 ◽  
Vol 50 (07) ◽  
pp. 1499-1510 ◽  
Author(s):  
Wei Chen ◽  
Xiao-Yan Lu ◽  
Bei-Hua Xu ◽  
Wei-guo Yu ◽  
Zi-niu Zhou ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Rational Design ◽  
Pd Nanoparticles ◽  
Water Soluble ◽  
Tem Analysis ◽  
Arylboronic Acids ◽  
Design And Synthesis ◽  
Black Precipitate ◽  
Aryl Bromides ◽  
Carboxylic Groups

Eight precatalysts containing carboxylic-functionalized thiourea ligands are prepared and their activities and recyclability are evaluated in aerobic aqueous Suzuki–Miyaura reactions. A bulky monothiourea–Pd complex, functionalized with four carboxylic groups, shows the best activity and recyclability in the coupling of aryl bromides with arylboronic acids. The catalyst can be reused at least five times without any significant reduction in its catalytic activity. TEM analysis and the confirmed catalytic activity of the observed black precipitate reveal that Pd nanoparticles are formed during the reactions and are stabilized by the carboxylic-functionalized thiourea ligands.

The effect of preparation conditions of a platinum hydrogentaion catalyst on its activity and on the dispersity of platinum crystallites

1979 ◽  
Vol 44 (9) ◽  
pp. 2619-2623 ◽  
Author(s):  
Jiří Hanika ◽  
Karel Sporka ◽  
Vlastimil Růžička ◽  
Jaroslav Bauer
Keyword(s):  
Catalytic Activity ◽  
Liquid Phase ◽  
Hydrogen Chloride ◽  
Active Carbon ◽  
Hydrogenation Catalyst ◽  
Chloroplatinic Acid ◽  
Metallic Platinum ◽  
Preparation Conditions

The paper deals with the preparation of a hydrogenation catalyst, 5% of platinum on active carbon. The support was saturated with aqueous chloroplatinic acid or platinum tetrachloride. After calcination in streaming nitrogen the catalyst was reduced with hydrogen. We studied the effects of temperatures of the calcination and the reduction on 1) the formation of hydrogen chloride in the course of calcination and the following reduction, 2) the dispersity of metallic platinum and 3) the catalytic activity for hydrogenation of 2-methyl-3-butene-2-ol and nitrobenzene in liquid phase. The catalytic activity was found to be proportional to the dispersity of platinum.

scholarly journals Water-soluble gold nanoparticles: recyclable catalysts for the reduction of aromatic nitro compounds in water

RSC Advances ◽  
2020 ◽  
Vol 10 (26) ◽  
pp. 15065-15071 ◽  
Author(s):  
Gustavo A. Monti ◽  
N. Mariano Correa ◽  
R. Darío Falcone ◽  
Gustavo F. Silbestri ◽  
Fernando Moyano
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Pure Water ◽  
Nitro Compounds ◽  
Water Soluble ◽  
Imidazolium Salts ◽  
Aromatic Nitro Compounds ◽  
Recyclable Catalysts ◽  
Aromatic Nitro

A structure/catalytic activity study of water-soluble gold nanoparticles, stabilized by zwitterionic ligands derived from imidazolium salts, in the reduction of aromatic nitro compounds in pure water, as well as their recyclability, was performed.

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