In situ rapid growth of fluorescent silicon nanoparticles at room temperature and under atmospheric pressure

2016 ◽  
Vol 52 (92) ◽  
pp. 13444-13447 ◽  
Author(s):  
Yiling Zhong ◽  
Bin Song ◽  
Fei Peng ◽  
Yanyan Wu ◽  
Sicong Wu ◽  
...  

Fluorescent and small-sized silicon nanoparticles (SiNPs) can be quickly created through in situ bottom-up growth under mild reaction conditions.

2019 ◽  
Vol 41 (6) ◽  
pp. 1039-1039
Author(s):  
Yingguo Fang and Jie Yan Yingguo Fang and Jie Yan

A novel and efficient alkoxylselenenylation from alkenes, diselenides, and alcohols mediated by iodine is developed, with which a series of β-alkoxy selenides are synthesized. In this procedure, firstly, I2 reacts with diselenide to form in situ the active electrophilic selenium species RSeI, then following an electrophilic addition of it to alkenes provides β-alkoxy selenides with high regioselectivity and in good yields. This new method for achieving β-alkoxy selenides has some advantages over other methods such as using available and cheap iodine as the oxidizing species at room temperature, which makes this reaction has milder reaction conditions and simpler procedure.


2011 ◽  
Vol 396-398 ◽  
pp. 1283-1286
Author(s):  
Jian Peng Zhu ◽  
Chun Hu Li ◽  
Jia Ling Chen ◽  
Ying Wei Luo

Abstract. Investigation of polymer resin as catalyst in the oxidative desulfurization (ODS) process has revealed that the method can be applied to make a relative high removal of sulfur compounds. The reaction conditions, including temperature, amount of oxidant and reaction time were studied. The best result occurs under mild conditions with respect to room temperature and atmospheric pressure, to remove 75.54% of the totle sulfur content in the presence of H2O2 with an O/S molar ratio of 17. Possible mechanism is also disscussed.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Saadia Oubaassine ◽  
Angela Köckritz ◽  
Reinhard Eckelt ◽  
Andreas Martin ◽  
Mustapha Ait Ali ◽  
...  

In a one-step procedure, various β-bromoalcohols were synthesized from natural terpenes in good to excellent yields. Using different catalysts, the reaction was carried out at room temperature, with H2O as nucleophile and N-bromosuccinimide as a bromine source under mild reaction conditions. The synthesized β-bromoalcohols were subsequently converted in situ to the corresponding epoxides in good yields.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1643 ◽  
Author(s):  
Oleg A. Usoltsev ◽  
Anna Yu. Pnevskaya ◽  
Elizaveta G. Kamyshova ◽  
Andrei A. Tereshchenko ◽  
Alina A. Skorynina ◽  
...  

Adsorption of ethylene on palladium, a key step in various catalytic reactions, may result in a variety of surface-adsorbed species and formation of palladium carbides, especially under industrially relevant pressures and temperatures. Therefore, the application of both surface and bulk sensitive techniques under reaction conditions is important for a comprehensive understanding of ethylene interaction with Pd-catalyst. In this work, we apply in situ X-ray absorption spectroscopy, X-ray diffraction and infrared spectroscopy to follow the evolution of the bulk and surface structure of an industrial catalysts consisting of 2.6 nm supported palladium nanoparticles upon exposure to ethylene under atmospheric pressure at 50 °C. Experimental results were complemented by ab initio simulations of atomic structure, X-ray absorption spectra and vibrational spectra. The adsorbed ethylene was shown to dehydrogenate to C2H3, C2H2 and C2H species, and to finally decompose to palladium carbide. Thus, this study reveals the evolution pathway of ethylene on industrial Pd-catalyst under atmospheric pressure at moderate temperatures, and provides a conceptual framework for the experimental and theoretical investigation of palladium-based systems, in which both surface and bulk structures exhibit a dynamic nature under reaction conditions.


2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Scott J. Kirkby

Chlorobenzene was reacted with NO2, in the initially acid-free zeolite NaZSM-5, to yield para-chloronitrobenzene exclusively. The precursors were loaded sequentially into self-supporting pellets of the zeolite, contained within a stainless steel cell, from the gas phase. The reaction proceeds spontaneously at room temperature. It is, however, very temperature dependent and effectively ceases at zero degrees Celsius. The reaction was monitored in situ using FT-IR. The active nitrating agent is formed from the partial electron donation by the NO2 to the Na+ cations present in the zeolite lattice. Under the reaction conditions, chlorobenzene is not readily mobile through the pore system; thus, only the molecules adsorbed near a cation site react to form para-chloronitrobenzene.


Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 508 ◽  
Author(s):  
Jie Zhang ◽  
Jiarui Chang ◽  
Ting Liu ◽  
Bula Cao ◽  
Yazhou Ding ◽  
...  

The reduction of CO2 is of great importance. In this paper, different types of bis(phosphinite) (POCOP) pincer nickel complexes, [2,6-(R2PO)2C6H3]NiX (R = tBu, iPr, Ph; X = SH, N3, NCS), were applied to the catalytic hydroboration of CO2 with catecholborane (HBcat). It was found that pincer complexes with tBu2P or iPr2P phosphine arms are active catalysts for this reaction in which CO2 was successfully reduced to a methanol derivative (CH3OBcat) with a maximum turnover frequency of 1908 h−1 at room temperature under an atmospheric pressure of CO2. However, complexes with phenyl-substituted phosphine arms failed to catalyze this reaction—the catalysts decomposed under the catalytic conditions. Complexes with iPr2P phosphine arms are more active catalysts compared with the corresponding complexes with tBu2P phosphine arms. For complexes with the same phosphine arms, the catalytic activity follows the series of mercapto complex (X = SH) ≈ azido complex (X = N3) >> isothiocyanato complex (X = NCS). It is believed that all of these catalytic active complexes are catalyst precursors which generate the nickel hydride complex [2,6-(R2PO)2C6H3]NiH in situ, and the nickel hydride complex is the active species to catalyze this reaction.


Nanoscale ◽  
2015 ◽  
Vol 7 (18) ◽  
pp. 8566-8573 ◽  
Author(s):  
A. Malumbres ◽  
G. Martínez ◽  
J. L. Hueso ◽  
J. Gracia ◽  
R. Mallada ◽  
...  

In situ stabilization via fluoride-mediated room-temperature hydrosilylation of silicon nanocrystals synthesized by laser-enhanced reaction.


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