scholarly journals Synthesis of NiO/Y2O3/ZrO2 Catalysts Prepared by One-Step Polymerization Method and Their Use in the Syngas Production from Methane

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Yvan J. O. Asencios ◽  
Elisabete M. Assaf
Keyword(s):  
Nickel Concentration ◽  
Low Carbon ◽  
Syngas Production ◽  
Oxidation Of Methane ◽  
One Step ◽  
The One ◽  
Nickel Dispersion ◽  
Geometric Morphology ◽  
Polymerization Method ◽  
Step Polymerization

In this work, the production of Syngas (H2/CO) from oxidative reforming of methane (ORM) and partial oxidation of methane (POM) over NiO/Y2O3/ZrO2 catalysts was studied. The nickel concentration was varied (ranging from 0 to 40 wt.%) aiming to optimize the performance in ORM and POM reactions; these reactions were carried out at 750°C and 1 atm for 6 hours. The catalysts were prepared by the one-step polymerization method (OSP) and characterized by different techniques. This method led to production of materials of smaller crystallite size than others of similar composition prepared under other methods; the catalysts presented good nickel dispersion, well-defined crystalline structure, and well-defined geometrical morphology. Additionally, the OSP method was advantageous because it was carried out in a single calcination step. The catalyst containing 20% wt. of nickel (20Ni20YZ sample) showed the highest methane conversion, high selectivity to H2 and CO, low carbon deposition rates, and, curiously, the best geometric morphology. The results of this paper also demonstrated that the nickel concentration in the mixture strongly influenced the morphology of the catalysts; therefore, the morphology also influenced the catalytic performances during the Syngas production reactions.

scholarly journals Towards coupling direct activation of methane with in situ generation of H2O2

2019 ◽  
Vol 9 (18) ◽  
pp. 5142-5149
Author(s):  
Amin Delparish ◽  
Shamayita Kanungo ◽  
John van der Schaaf ◽  
M. Fernanda Neira d'Angelo
Keyword(s):  
Direct Activation ◽  
Oxidation Of Methane ◽  
One Step ◽  
In Situ Generation ◽  
The One ◽  
Shed Light

This study aims to shed light on the one-step oxidation of methane to methanol with in situ generated H2O2 by means of a wall-coated catalytic microreactor.

Encapsulation of Luminescent Quantum Nanodots in Polystyrene Nanocapsules by Microemulsion Polymerization

2005 ◽  
Vol 23 ◽  
pp. 19-22 ◽  
Author(s):  
Xiaotun Yang ◽  
Ning Huang ◽  
Yong Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Dots ◽  
Fluorescence Microscopy ◽  
Fluorescence Spectroscopy ◽  
Microemulsion Polymerization ◽  
Transmission Electron ◽  
One Step ◽  
The One ◽  
Polymerization Method

This paper reported on the one-step synthesis of polystyrene-quantum dots (PS@QD)nanoparticles using microemulsion polymerization method. The synthesized QD and PS@QD nanoparticles were characterized by UV, fluorescence spectroscopy, transmission electron microscopy (TEM) and fluorescence microscopy. The PS@QD is highly luminescent, which have the potential to be used as fluorescent probes in biological staining and diagnostics.

A Study on the Rearrangement of Dialkyl 1-Aryl-1-hydroxymethylphosphonates to Benzyl Phosphates

2020 ◽  
Vol 24 (4) ◽  
pp. 465-471 ◽  
Author(s):  
Zita Rádai ◽  
Réka Szabó ◽  
Áron Szigetvári ◽  
Nóra Zsuzsa Kiss ◽  
Zoltán Mucsi ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Room Temperature ◽  
Phase Transfer ◽  
One Pot ◽  
Substrate Dependence ◽  
Triethylbenzylammonium Chloride ◽  
One Step ◽  
The Pudovik Reaction ◽  
The One ◽  
Solid Liquid

The phospha-Brook rearrangement of dialkyl 1-aryl-1-hydroxymethylphosphonates (HPs) to the corresponding benzyl phosphates (BPs) has been elaborated under solid-liquid phase transfer catalytic conditions. The best procedure involved the use of triethylbenzylammonium chloride as the catalyst and Cs2CO3 as the base in acetonitrile as the solvent at room temperature. The substrate dependence of the rearrangement has been studied, and the mechanism of the transformation under discussion was explored by quantum chemical calculations. The key intermediate is an oxaphosphirane. The one-pot version starting with the Pudovik reaction has also been developed. The conditions of this tandem transformation were the same, as those for the one-step HP→BP conversion.

One-step plasma deposited thin SiO x C y films for corrosion resistance of low carbon steel

2020 ◽  
pp. 1-19
Author(s):  
Alaa Fahmy ◽  
Mansour El Sabbagh ◽  
Mahmoud Bedair ◽  
Amr Gangan ◽  
Mohsen El-Sabbah ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
One Step

scholarly journals One-Year Clinical Evaluation of the Bonding Effectiveness of a One-Step, Self-Etch Adhesive in Noncarious Cervical Lesion Therapy

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Babacar Faye ◽  
Mouhamed Sarr ◽  
Khaly Bane ◽  
Adjaratou Wakha Aidara ◽  
Seydina Ousmane Niang ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Retention Rate ◽  
Recall Rate ◽  
Acid Etching ◽  
Significant Difference ◽  
Usphs Criteria ◽  
One Step ◽  
One Year ◽  
The One ◽  
Self Etch

This study evaluated the one-year clinical performance of a one-step, self-etch adhesive (Optibond All-in-One, Kerr, CA, USA) combined with a composite (Herculite XRV Ultra, Kerr Hawe, CA, USA) to restore NCCLs with or without prior acid etching. Restorations performed by the same practitioner were evaluated at baseline and after 3, 6, and 12 months using modified USPHS criteria. At 6 months, the recall rate was 100%. The retention rate was 84.2% for restorations with prior acid etching, but statistically significant differences were observed between baseline and 6 months. Without acid etching, the retention rate was 77%, and no statistically significant difference was noted between 3 and 6 months. Marginal integrity (93.7% with and 87.7% without acid etching) and discoloration (95.3% with and 92.9% without acid etching) were scored as Alpha or Bravo, with better results after acid etching. After one year, the recall rate was 58.06%. Loss of pulp vitality, postoperative sensitivity, or secondary caries were not observed. After one year retention rate was of 90.6% and 76.9% with and without acid conditioning. Optibond All-in-One performs at a satisfactory clinical performance level for restoration of NCCLs after 12 months especially after acid etching.

scholarly journals Building up cyclodextrins from scratch – templated enzymatic synthesis of cyclodextrins directly from maltose

2021 ◽  
Author(s):  
Dennis Larsen ◽  
Sophie R. Beeren
Keyword(s):  
Enzymatic Synthesis ◽  
Combinatorial Libraries ◽  
One Step ◽  
The One ◽  
Kinetic Trapping

Template-induced kinetic trapping of specific cyclodextrins in enzyme-mediated dynamic combinatorial libraries of linear and cyclic α-glucans enables the one-step synthesis of cyclodextrins from maltose in water.

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