نتایج جستجو برای: solid base catalyst

تعداد نتایج: 481891  

Journal: :Angewandte Chemie 2007
Hengquan Yang Lei Zhang Lin Zhong Qihua Yang Can Li

The solid catalyst with high catalytic activity and enantioselectivity in the hydrolytic kinetic resolution (HKR) of epoxides was prepared by confining Co(Salen) in the nanocage of SBA-16 through reducing the pore entrance size using a silylation method. It was found that the activity of the solid catalysts increased with the number of [Co(Salen)] molecules per nanocage increasing, and the soli...

2018
Yingjie Zhou Iman Noshadi Hao Ding Jingjing Liu Richard S. Parnas Abraham Clearfield Min Xiao Yuezhong Meng Luyi Sun

In this study, a solid acid was prepared by the sulfonation of surface modified α-zirconium phosphate (ZrP) single-layer nanosheets (SO3H@ZrP), and the prepared solid acid was investigated for the esterification of oleic acid with methanol to produce biodiesel. For comparison, liquid H2SO4 and commercial Amberlyst® 15 catalyst were also evaluated for the same reaction under the same conditions....

Journal: :Catalysts 2023

Under the energy crisis and with greenhouse gases causing an ecological imbalance, biofuel has attracted worldwide attention due to its sustainability low net-carbon emission. For years, traditional biodiesel industry been demanding a high-performance solid base catalyst. Its poor reusability is bottleneck for promising calcium-based solid-base In this work, we successfully adopted new silicate...

2016
Wenjie Dong Zheng Shen Boyu Peng Minyan Gu Xuefei Zhou Bo Xiang Yalei Zhang

Lactic acid is an important platform molecule in the synthesis of a wide range of chemicals. However, in aqueous solutions without alkali, its efficient preparation via the direct catalysis of sugars is hindered by a side dehydration reaction to 5-hydroxymethylfurfural due to Brønsted acid, which originates from organic acids. Herein, we report that a previously unappreciated combination of com...

2017
Pedro Leo Gisela Orcajo David Briones Guillermo Calleja Manuel Sánchez-Sánchez Fernando Martínez

The activity and recyclability of Cu-MOF-74 as a catalyst was studied for the ligand-free C-O cross-coupling reaction of 4-nitrobenzaldehyde (NB) with phenol (Ph) to form 4-formyldiphenyl ether (FDE). Cu-MOF-74 is characterized by having unsaturated copper sites in a highly porous metal-organic framework. The influence of solvent, reaction temperature, NB/Ph ratio, catalyst concentration, and b...

Journal: :The Journal of organic chemistry 2002
Ryoichi Kuwano Masaru Utsunomiya John F Hartwig

The amination of aryl halides in the presence of inexpensive and air-stable alkali metal hydroxide bases and Pd[P(t-Bu)3]2 as catalyst gave arylamines in high yields. The reactions were conducted with a catalytic amount of cetyltrimethylammonium bromide as phase-transfer agent and either aqueous hydroxide or solid hydroxide in the presence of water. This combination of alkali metal hydroxide ba...

Journal: :journal of nanostructures 2013
a. tadjarodi m. haghverdi v. mohammadi m. rajabi

the silica aerogel was prepared by the acid–base sol–gel polymerization of tetraethylorthosilicate precursor followed by ambient pressure drying. the prepared silica aerogels were characterized by fourier transform infrared )ft-ir(, thermo-gravimetric and differential thermal analysis )tg/dta(, x-ray diffractometer )xrd(, energy dispersive x-ray microanalysis )edx(, brunauer–emmitt–teller (bet)...

Journal: :Molecules 2016
Kei Saito Koji Miyamoto Sepa Nanayakkara Hirotaka Ihara Milton T W Hearn

A new solid phase catalyst, poly(N-4-vinylbenzyl-1,4,7-triazacyclononane) copper(I) complex, grafted onto polystyrene particles, has been employed for the oxidative polymerization of 2,6-dimethylphenol using an aqueous biphasic (water/toluene) solvent system. The solid catalyst was synthesized by first grafting N-(4-vinylbenzyl)-1,4,7-triaza-cyclononane onto polystyrene particles using a radica...

2012
K. Ravi B. Krishnakumar M. Swaminathan

A new BiCl3-loaded montmorillonite K10 catalyst has been prepared by solid dispersion method and was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and cyclic voltammetry (CV) measurements. BiCl3 loaded K10 (BiCl3-K10) has been used as solid acid catalyst for the synthesis of azine derivatives from benzophenone hydrazone and ketones/aldehydes by ...

2012
Zahed Karimi-Jaberi Korosh Mohammadi

β-acetamido ketones were synthesized in excellent yields through one-pot condensation reaction of aldehydes, acetophenones, acetyl chloride, and acetonitrile in the presence of boric acid as a solid heterogeneous catalyst at room temperature. It is the first successful report of boric acid that has been used as solid acid catalyst for the preparation of β-acetamido ketones. The remarkable advan...

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