scholarly journals Graphdiyne-actinyl complexes as potential catalytic materials: A DFT perspective from their structural, bonding, electronic and redox properties

2020 ◽  
Vol 13 (3) ◽  
pp. 4564-4576 ◽  
Author(s):  
Raza ullah shah Bacha ◽  
Ting-Ting Lin ◽  
Jun Yao ◽  
Qing-Jiang Pan
2018 ◽  
Vol 24 (71) ◽  
pp. 18998-19009 ◽  
Author(s):  
Ming-Xing Zhang ◽  
Jing Zhang ◽  
Xuyang Jin ◽  
Xiaona Sun ◽  
Jun Yin ◽  
...  

2020 ◽  
Vol 16 ◽  
Author(s):  
Anping Wang ◽  
Heng Zhang ◽  
Hu Li ◽  
Song Yang

Background: With the gradual decrease of fossil energy, the development of alternatives to fossil energy has attracted more and more attention. Biodiesel is considered to be the most potent alternative to fossil energy, mainly due to its green, renewable and biodegradable advantages. The stable, efficient and reusable catalysts are undoubtedly the most critical in the preparation of biodiesel. Among them, nanoporous carbon-based acidic materials are very important biodiesel catalysts. Objective: The latest advances of acidic nanoporous carbon catalysts in biodiesel production was reviewed. Methods: Biodiesel is mainly synthesized by esterification and transesterification. Due to the important role of nanoporous carbon-based acidic materials in the catalytic preparation of biodiesel, we focused on the synthesis, physical and chemical properties, catalytic performance and reusability. Results: Acidic catalytic materials have a good catalytic performance for high acid value feedstocks. However, the preparation of biodiesel with acid catalyst requires relatively strict reaction conditions. The application of nanoporous acidic carbon-based materials, due to the support of carbon-based framework, makes the catalyst have good stability and unique pore structure, accelerates the reaction mass transfer speed and accelerates the reaction. Conclusion: Nanoporous carbon-based acidic catalysts have the advantages of suitable pore structure, high active sites, and high stability. In order to make these catalytic processes more efficient, environmentally friendly and low cost, it is an important research direction for the future biodiesel catalysts to develop new catalytic materials with high specific surface area, suitable pore size, high acid density, and excellent performance.


1981 ◽  
Vol 46 (5) ◽  
pp. 1237-1247
Author(s):  
Zdeněk Prokop ◽  
Karel Setínek

The catalyst containing redox sites in addition to acid functional groups was prepared by sulphonation of a macroporous chloromethylated styrene-divinylbenzene copolymer with concentrated sulphuric acid at elevated temperatures. Its activity was tested for the oxidation of 2-propanol by molecular oxygen at 120 °C and was found to be comparable to that of the iridium on carbon catalyst.Neutralisation of acid functional groups by alkali metal led to proportional decrease in the oxidation activity. The results of EPR spectroscopic study of these catalysts show that the redox properties of the polymer are caused by carbon clusters which are capable of electron exchange.


1980 ◽  
Vol 45 (2) ◽  
pp. 335-338 ◽  
Author(s):  
Adéla Kotočová ◽  
Ulrich Mayer

The solvation effect of a number of nonaqueous polar solvents was studied on the oxidation-reduction properties of the [Co(en)3]3+-[Co(en)3]2+ system. Interactions of these ions with the solvent molecules are discussed in terms of their coordination, which is accompanied by a specific interaction of the Lewis acid-base type, namely formation of a hydrogen bond between the interacting particles. This is the main controlling factor of the redox properties of the studied system.


2001 ◽  
Vol 66 (7) ◽  
pp. 1062-1077 ◽  
Author(s):  
Maarten J. Bakker ◽  
Tapani A. Pakkanen ◽  
František Hartl

Electrochemical properties of tetrahedral clusters [H2Ru2Rh2(CO)12], [HRuRh3(CO)12] and [Rh4(CO)12] were investigated in order to evaluate the influence of metal core composition in the series [H4-xRu4-xRhx(CO)12] (x = 0-4). The cluster [H3Ru3Rh(CO)12] was not available in sufficient quantities. As reported for [H4Ru4(CO)12], electrochemical reduction of the hydride-containing clusters [H2Ru2Rh2(CO)12] and [HRuRh3(CO)12] also results in (stepwise) loss of hydrogen, producing the anions [HRu2Rh2(CO)12]-, [Ru2Rh2(CO)12]2- and [RuRh3(CO)12]-. These anions can also be prepared from the neutral parent clusters via chemical routes. Electrochemical reduction of [Rh4(CO)12] does not result in the formation of any stable tetranuclear anion. Instead, [Rh5(CO)15]- and [Rh6(CO)15]2- are the major reduction products detected in the course of IR spectroelectrochemical experiments. Most likely, these cluster species are formed from the secondary CO-loss product [Rh4(CO)11]2- by fast redox condensation reactions. Their reoxidation regenerates parent [Rh4(CO)12], together with some [Rh6(CO)16]. Unlike [H4Ru4(CO)12] that undergoes photochemical CO-dissociation, [H2Ru2Rh2(CO)12] and [Rh4(CO)12] are completely photostable in neat hexane and dichloromethane as well as in the presence of oct-1-ene.


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