Reduction of N2 to NH3 Catalyzed by A Keggin-Type Polyoxometalate-Supported Dual-Atom Catalyst

2021 ◽  
Author(s):  
Yu Wang ◽  
Rui-Cheng Qin ◽  
Dan Wang ◽  
Chun-Guang Liu
Keyword(s):  
Alternative Route ◽  
Reaction Conditions ◽  
Bosch Process ◽  
Keggin Type ◽  
Dual Atom

Because of the harsh reaction conditions and relatively low NH3 yield of Haber-Bosch process for synthesized ammonia industry, it is highly desirable to develop an alternative route for more efficient...

Oxidation of Benzaldehyde to Benzoic Acid with Aqueous Hydrogen Peroxide over Dodecatungstophosphoric Acid

2013 ◽  
Vol 781-784 ◽  
pp. 219-222
Author(s):  
Qiu Ying Huang ◽  
Bei Bei Dong ◽  
Xiu Cheng Zheng
Keyword(s):  
Hydrogen Peroxide ◽  
Benzoic Acid ◽  
Catalytic Reaction ◽  
Type Structure ◽  
Optimal Parameters ◽  
Reaction Parameters ◽  
Aqueous Hydrogen Peroxide ◽  
Reaction Conditions ◽  
Prepared Sample ◽  
Keggin Type

Dodecatungstophosphoric acid was synthesized and used as catalyst for oxidation of benzaldehyde to benzoic acid with aqueous hydrogen peroxide. The effect of various catalytic reaction parameters including time, temperatures, and the amount of catalyst on the yield of benzoic acid was investigated in details. The results indicated that the as-prepared sample was in the keggin-type structure and the optimal parameters under the reaction conditions were as follows: 0.5 g of catalyst, reacted at 80 C for 5 h.

scholarly journals Phosgene-free synthesis of 1,3-diphenylurea via catalyzed reductive carbonylation of nitrobenzene

2012 ◽  
Vol 84 (3) ◽  
pp. 473-484 ◽  
Author(s):  
Andrea Vavasori ◽  
Lucio Ronchin
Keyword(s):  
Phenyl Isocyanate ◽  
High Yield ◽  
Diphosphine Ligands ◽  
Alternative Route ◽  
Reaction Conditions ◽  
Bite Angle ◽  
Reductive Carbonylation ◽  
One Step ◽  
Optimum Reaction ◽  
Synthetic Intermediate

1,3-Diphenylurea (DPU) has been proposed as a synthetic intermediate for phosgene-free synthesis of methyl N-phenylcarbamate and phenyl isocyanate, which are easily obtained from the urea by reaction with methanol. Such an alternative route to synthesis of carbamates and isocyanates necessitates an improved phosgene-free synthesis of the corresponding urea. In this work, it is reported that Pd(II)-diphosphine catalyzed reductive carbonylation of nitrobenzene in acetic acid (AcOH)-methanol proceeds in high yield and selectivity as a one-step synthesis of DPU. We have found that the catalytic activity and selectivity of this process depends on solvent composition and on the bite angle of the diphosphine ligands. Under optimum reaction conditions, yields in excess of 90 molar % and near-quantitative selectivity can be achieved.

An Alternative Route to 2-Bromo-Estradiols and 2-Iodo-Estradiols From Estradiol

1987 ◽  
Vol 40 (2) ◽  
pp. 303 ◽  
Author(s):  
DJ Pert ◽  
DD Ridley
Keyword(s):  
Methyl Ether ◽  
Alternative Route ◽  
Reaction Conditions ◽  
Careful Choice ◽  
Ether Derivative ◽  
Trimethylsilyl Derivatives

Through careful choice of reaction conditions, alkylation of estradiol with chloromethyl methyl ether may yield either the 3,17β-bis(methoxymethy1) ether or the 3-methoxymethyl ether derivative. Treatment of either of these protected estradiols with s- butyllithium, then with trimethylsilyl chloride affords, regioselectively, the 2-trimethylsilyl derivatives which can conveniently be converted into 2-bromo-or 2-iodo-estradiol.

Undecagold labeling of tRNA

1991 ◽  
Vol 49 ◽  
pp. 44-45
Author(s):  
James F. Hainfeld ◽  
Kyra M. Alford ◽  
Mathias Sprinzl ◽  
Valsan Mandiyan ◽  
Santa J. Tumminia ◽  
...  
Keyword(s):  
High Resolution ◽  
Transmission Electron Micrograph ◽  
Anticodon Loop ◽  
Electron Micrograph ◽  
Reaction Conditions ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

The undecagold (Au11) cluster was used to covalently label tRNA molecules at two specific ribonucleotides, one at position 75, and one at position 32 near the anticodon loop. Two different Au11 derivatives were used, one with a monomaleimide and one with a monoiodacetamide to effect efficient reactions.The first tRNA labeled was yeast tRNAphe which had a 2-thiocytidine (s2C) enzymatically introduced at position 75. This was found to react with the iodoacetamide-Aun derivative (Fig. 1) but not the maleimide-Aun (Fig. 2). Reaction conditions were 37° for 16 hours. Addition of dimethylformamide (DMF) up to 70% made no improvement in the labeling yield. A high resolution scanning transmission electron micrograph (STEM) taken using the darkfield elastically scattered electrons is shown in Fig. 3.

Dimensionally-Controlled Hydrothermal Tm3+-doped Oxidic Nanocrystals and Their Photoluminescence Properties

2010 ◽  
Vol 1247 ◽  
Author(s):  
Rocío Calderón-Villajos ◽  
Carlos Zaldo ◽  
Concepción Cascales
Keyword(s):  
Single Crystals ◽  
Fluorescence Lifetimes ◽  
Photoluminescence Properties ◽  
Reaction Conditions ◽  
Hydrothermal Processes ◽  
Bulk Single Crystals ◽  
Template Free ◽  
Reaction Media

AbstractControlled reaction conditions in simple, template-free hydrothermal processes yield Tm-Lu2O3 and Tm-GdVO4 nanocrystals with well-defined specific morphologies and sizes. In both oxide families, nanocrystals prepared at pH 7 reaction media exhibit photoluminescence in ∼1.95 μm similar to bulk single crystals. For the lowest Tm3+ concentration (0.2 % mol) in GdVO4 measured 3H4 and 3F4 fluorescence lifetimes τ are very near to τrad.

Exploring the Diversity of Religion

2010 ◽  
Vol 4 (1) ◽  
pp. 46-66
Author(s):  
Arkotong Longkumer
Keyword(s):  
Cultural Identity ◽  
Nation Building ◽  
Religious Movement ◽  
The Political ◽  
Alternative Route ◽  
British Colonialism ◽  
The North

This article considers the importance of “religion” and “identity” in the process of fieldwork in the North Cachar Hills, Assam, India. The political sensitivities in the region provided a difficult context in which to do fieldwork. This is chiefly because of the various armed insurrections, which have arisen as a consequence of the complicated remnants of British colonialism (1834–1947), and the subsequent post-independence challenge of nation building in India. This article raises important methodological questions concerning fieldwork and the relational grounding of the fieldworker relative to the inside/outside positions. It reflects on these issues by discussing the Heraka, a Zeme Naga religious movement. Their ambiguity and “in-between” character accommodates both the “neo-Hindu” version of a nation or Hindutva (Hinduness) and the larger Naga (primarily Christian) assertion of their own cultural and religious autonomy. The Heraka provides an alternative route into ideas of nationhood, religious belonging and cultural identity.

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