نتایج جستجو برای: zn fealumina catalyst
تعداد نتایج: 82294 فیلتر نتایج به سال:
abstract in first part of this project, the use of a new and biguanid-like catalyst supported on silica as a recyclable catalyst provides a new route for the synthesis of a variety of arylalkylidene rhodanine derivatives through knoevenagle reaction in at present of solvent at room temperature. rhodanine derivatives and especially arylalkylidene rhodanines have proven to be attractive compound...
The fabrication of flexible, stretchable and rechargeable devices with a high energy density is critical for next-generation electronics. Herein, fiber-shaped Zn-air batteries, are realized for the first time by designing aligned, cross-stacked and porous carbon nanotube sheets simultaneously that behave as a gas diffusion layer, a catalyst layer, and a current collector. The combined remarkabl...
Seed/catalyst-free growth of zinc oxide nanostructures on multilayer graphene by thermal evaporation
We report the seed/catalyst-free growth of ZnO on multilayer graphene by thermal evaporation of Zn in the presence of O2 gas. The effects of substrate temperatures were studied. The changes of morphologies were very significant where the grown ZnO structures show three different structures, i.e., nanoclusters, nanorods, and thin films at 600°C, 800°C, and 1,000°C, respectively. High-density ver...
Carbonic anhydrases (CAs, EC 4) are zinc containing metalloenzymes. The active site of these enzymes contains a Zn (II) ion Co-ordinated by three histidine residues and a water molecule/hydroxide ion. Four distinct gene families encode them and distributed throughout the phylogenetic tree. Presently 16 different CA isoforms of alpha family have been isolated and characterized in mammals. They c...
Ephedrine-derived sulfamide-amine alcohol 3 was found to be an effective catalyst for the asymmetric phenylacetylene addition to aldehydes at room temperature without using Ti(O(i)Pr)4 and Zn(OTf)2. It afforded the propargylic alcohols in high yields (up to 99%) and good enantioselectivities (up to 84% ee), which were much higher than that based on N-methylephedrine under the same reaction cond...
Selective esterification of aliphatic and aromatic carboxylic acids with various alcohols is studied using triphenylphosphine, I2, and a catalytic amount of Zn(OTf)2. Use of this catalyst allows the formation of esters at a faster rate with good to excellent yield by activating the in situ generated acyloxyphosphonium ion intermediate. During the esterification process, both their aromatic and ...
This paper presents the results of a study on catalytic activity and selectivity nickel palladium catalysts in hydrogenation reactions nitro- acetylene compounds. It was shown that phenylacetylene depend nature modifying additives (Cu, Zn, Ti, Cr, Bi, Ti–Cu, Mn, Fe), based polymer metal complexes depends method their preparation. found for certain concentrations active phase (0.8 wt.%) potassiu...
Catalytic dehydrogenation of ethanol produces acetaldehyde, an important precursor for several value-added chemicals such as acetic acid and acetate esters. In this paper, we demonstrate that Zn-containing MFI zeolites are highly active selective catalysts process. Furthermore, show their activity selectivity depend on the chemical composition preparation catalysts. The best catalyst comprises ...
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