ChemInform Abstract: ELECTROCHEMISTRY OF HOMOGENEOUS CATALYSTS: CORRELATION OF THE ELECTROCHEMISTRY AND THE ZIEGLER-NATTA CATALYTIC ACTIVITY OF METAL ACETYLACETONATE COMPLEXES

1984 ◽  
Vol 15 (33) ◽  
Author(s):  
C. W. ANDERSON ◽  
K. R. LUNG ◽  
T. A. NILE
Keyword(s):  
Catalytic Activity ◽  
Homogeneous Catalysts ◽  
Metal Acetylacetonate

Get Rid of the Shackle from Supports: Construct Recoverable Semi-Homogeneous Catalysts with Attapulgite

2021 ◽  
Author(s):  
Ruixiang Guo ◽  
Gang Wang ◽  
Wei Liu ◽  
Zibei Yao ◽  
Wei-Sheng Liu
Keyword(s):  
Catalytic Activity ◽  
Homogeneous Catalysts ◽  
Immobilized Catalyst ◽  
Novel Strategy ◽  
Adsorption Desorption

Traditionally, the immobilized catalyst sacrifices a part of catalytic activity for its recyclability. To reproduce the catalytic activity of active specie, we construct a novel strategy called "adsorption-desorption-adsorption". Since the...

Hydroxy-substituted Cobalt Tetraphenylporphyrins as Electrocatalysts for the Reduction of O2

1997 ◽  
Vol 01 (02) ◽  
pp. 181-188 ◽  
Author(s):  
MAKOTO YUASA ◽  
BEAT STEIGER ◽  
FRED C. ANSON
Keyword(s):  
Aqueous Solution ◽  
Catalytic Activity ◽  
Pyrolytic Graphite ◽  
Porphyrin Ring ◽  
Homogeneous Catalysts ◽  
Graphite Electrodes ◽  
Adsorbed Molecules ◽  
Cobalt Porphyrins ◽  
Meso Position ◽  
Electron Reduction

The possible effects of the electron-donating properties of p-hydroxyphenyl groups on the catalytic activity of cobalt porphyrins toward the electro-reduction of O 2 were explored with three cobalt porphyrins having p-hydroxyphenyl substituents in the meso position of the porphyrin ring. The porphyrins were examined as electrocatalysts adsorbed on the surfaces of pyrolytic graphite electrodes in aqueous solution and as homogeneous catalysts dissolved in methanolic solutions. The adsorbed molecules exhibited a higher catalytic activity than those in solution and accomplished the reduction of a portion of the O 2 molecules reaching the electrode to H 2 O . However, the four-electron reduction was indirect, with H 2 O 2 being formed as an intermediate that was subsequently reduced. Although the introduction of the electron-donating p-hydroxyphenyl substituents on the porphyrin ring altered the catalytic activity of the cobalt porphyrins, the effect was not as great as can be obtained by coordinating ruthenium (II) complexes to π-accepting ligands in the meso position of the porphyrin ring.

scholarly journals Advances in Homogeneous Photocatalytic Organic Synthesis with Colloidal Quantum Dots

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 275 ◽  
Author(s):  
Dan-Yan Wang ◽  
Yu-Yun Yin ◽  
Chuan-Wei Feng ◽  
Rukhsana ◽  
Yong-Miao Shen
Keyword(s):  
Quantum Dots ◽  
Catalytic Activity ◽  
Organic Synthesis ◽  
Semiconductor Quantum Dots ◽  
Organic Reactions ◽  
Colloidal Quantum Dots ◽  
Recent Application ◽  
Organic Transformations ◽  
Homogeneous Catalysts ◽  
Extinction Coefficients

Colloidal semiconductor quantum dots (QDs) have been proven to be excellent photocatalysts due to their high photostability, large extinction coefficients, and tunable optoelectrical properties, and have attracted extensive attention by synthetic chemists. These excellent properties demonstrate its promise in the field of photocatalysis. In this review, we summarize the recent application of QDs as homogeneous catalysts in various photocatalytic organic reactions. These meaningful works in organic transformations show the unique catalytic activity of quantum dots, which are different from other semiconductors.

Advances in Catalytic Conversion of Syngas to Ethanol and Higher Alcohols

2016 ◽  
pp. 177-215
Author(s):  
Jie Sun ◽  
Shaolong Wan ◽  
Jingdong Lin ◽  
Yong Wang
Keyword(s):  
Catalytic Activity ◽  
Reaction Mechanism ◽  
Large Scale ◽  
Heterogeneous Catalysts ◽  
Higher Alcohols ◽  
Fischer Tropsch ◽  
Homogeneous Catalysts ◽  
High Productivity ◽  
Synthesis Catalysts ◽  
Prohibitive Cost

Ethanol and higher alcohols (C2+OH) have attracted much attention owing to their wide applications. They can be produced from syngas using homogeneous and heterogeneous catalysts. Although homogeneous catalysts exhibit high productivity and selectivity of C2+OH, difficulties in separating and recycling homogeneous catalysts remain challenging. Among heterogeneous catalysts, Rh-based catalysts show promising higher selectivity of C2+OH. However, prohibitive cost of Rh metal hinders its large-scale application. Non-noble metal based heterogeneous catalysts include modified methanol synthesis catalysts, modified Fischer-Tropsch (F-T) synthesis catalysts, and Mo/MoS2-based catalysts. Compared with the modified F-T synthesis catalysts and Mo/MoS2-based catalysts, production of undesired byproducts on modified Cu-based catalysts can be well suppressed. Here, the influences of additives and supports on catalytic activity of modified Cu-based catalysts are discussed. Reaction mechanism and development of novel reactors are also included.

scholarly journals Phosgene-free carbamoylation of aniline via dimethyl carbonate

2011 ◽  
Vol 84 (3) ◽  
pp. 695-705 ◽  
Author(s):  
Sandra Grego ◽  
Fabio Aricò ◽  
Pietro Tundo
Keyword(s):  
Catalytic Activity ◽  
Substrate Concentration ◽  
Heterogeneous Catalysts ◽  
Dimethyl Carbonate ◽  
Supported Catalysts ◽  
Temperature Influence ◽  
Reaction Conditions ◽  
Homogeneous Catalysts ◽  
Zinc Carbonate ◽  
Selection Of

The synthesis of N-phenylcarbamate from aniline and dimethyl carbonate (DMC) in the presence of homogeneous, supported heterogeneous, and heterogeneous catalysts was investigated in batch conditions. First, a selection of homogeneous catalysts was studied and their reactivity in the same reaction conditions was compared to zinc acetate, a catalyst extensively used for this reaction. Then the best homogeneous catalysts were supported on silica or alumina, and the resulting heterogeneous supported catalysts were tested for the carbamoylation of aniline. Finally, several heterogeneous catalysts were investigated. Zinc carbonate basic was shown to be the best catalyst, giving quantitative conversion and selectivity for the N-phenylcarbamate. Its catalytic activity was fully investigated taking into account substrate concentration, amount of catalysts, and temperature influence. Zinc carbonate was also shown to be recyclable, once it was recovered from the reaction mixture and calcinated.

High resolution electron microscopy of lanthanum phosphate crystals

1978 ◽  
Vol 36 (1) ◽  
pp. 274-275
Author(s):  
J. C. Wheatley ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
High Resolution ◽  
Petroleum Industry ◽  
High Resolution Electron Microscopy ◽  
Lanthanum Phosphate ◽  
Good Catalyst ◽  
Resolution Electron ◽  
Good Catalytic Activity ◽  
Physical And Chemical

Rare-earth phosphates are of particular interest because of their catalytic properties associated with the hydrolysis of many aromatic chlorides in the petroleum industry. Lanthanum phosphates (LaPO4) which have been doped with small amounts of copper have shown increased catalytic activity (1). However the physical and chemical characteristics of the samples leading to good catalytic activity are not known.Many catalysts are amorphous and thus do not easily lend themselves to methods of investigation which would include electron microscopy. However, the LaPO4, crystals are quite suitable samples for high resolution techniques.The samples used were obtained from William L. Kehl of Gulf Research and Development Company. The electron microscopy was carried out on a JEOL JEM-100B which had been modified for high resolution microscopy (2). Standard high resolution techniques were employed. Three different sample types were observed: 669A-1-5-7 (poor catalyst), H-L-2 (good catalyst) and 27-011 (good catalyst).

The design and catalytic performance of molybdenum active sites on an MCM-41 framework for the aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran

2019 ◽  
Vol 9 (3) ◽  
pp. 811-821 ◽  
Author(s):  
Zhao-Meng Wang ◽  
Li-Juan Liu ◽  
Bo Xiang ◽  
Yue Wang ◽  
Ya-Jing Lyu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Sites ◽  
Aerobic Oxidation ◽  
Catalytic Performance ◽  
Mcm 41

The catalytic activity decreases as –(SiO)3Mo(OH)(O) > –(SiO)2Mo(O)2 > –(O)4–MoO.

Sign in / Sign up

Export Citation Format

Share Document