نتایج جستجو برای: brønsted acidic

تعداد نتایج: 35712  

Journal: :The journal of physical chemistry letters 2013
Mehmed Z Ertem Steven J Konezny C Moyses Araujo Victor S Batista

Recent breakthroughs in electrochemical studies have reported aqueous CO2 reduction to formic acid, formaldehyde, and methanol at low overpotentials (-0.58 V versus SCE), with a Pt working electrode in acidic pyridine (Pyr) solutions. We find that CO2 is reduced by H atoms bound to the Pt surface that are transferred as hydrides to CO2 in a proton-coupled hydride transfer (PCHT) mechanism activ...

Journal: :Dalton transactions 2016
Hossein Naeimi Dorsa Aghaseyedkarimi

Novel multi-SO3H functionalized strong Brønsted acidic ionic liquid coated magnetite nanoparticles have been prepared and applied as catalyst for the synthesis of 2,4,5-trisubstituted imidazoles. The results showed that a novel catalyst was very efficient for the reaction and could be magnetically separated and reused at least 6 times with less reduction in its catalytic activity. Operational s...

2014
Subrata Das Ashim Jyoti Thakur Dhanapati Deka

Biodiesel was produced from high free fatty acid (FFA) Jatropha curcas oil (JCO) by two-stage process in which esterification was performed by Brønsted acidic ionic liquid 1-(1-butylsulfonic)-3-methylimidazolium chloride ([BSMIM]Cl) followed by KOH catalyzed transesterification. Maximum FFA conversion of 93.9% was achieved and it reduced from 8.15 wt% to 0.49 wt% under the optimum reaction cond...

2012
Adel A. Marzouk Vagif M. Abbasov Avtandil H. Talybov

Morpholinium hydrogen Sulphate as Brønsted acidic ionic liquid was used as an efficient and reusable catalyst for the onepot synthesis of 2,4,5-trisubstituted imidazoles that achieved by three component cyclocondensation of 1,2-dicarbonyl compound, aromatic or aliphatic aldehyde and ammonium acetate under thermal solvent-free conditions. The key advantages of this process are cost effectiveness...

2014
Scott E. Denmark Sergio Rossi Matthew P. Webster Hao Wang

A catalytic, enantioselective, Lewis base-catalyzed α-sulfenylation of silyl enol ethers has been developed. To avoid acidic hydrolysis of the silyl enol ether substrates, a sulfenylating agent that did not require additional Brønsted acid activation, namely N-phenylthiosaccharin, was developed. Three classes of Lewis bases-tertiary amines, sulfides, and selenophosphoramides-were identified as ...

2014
Ken Motokura Toshihide Baba Yasuhiro Iwasawa

This chapter deals with acid–base bifunctional heterogeneous catalyst surfaces with organofunctional groups. One of the most important issues for bifunctional heterogeneous catalysis is the coexistence of incompatible catalytic species, such as acid and base, nearby on a same solid particle surface. In nucleophilic reactions, acid–base bifunctional catalysts enable the activation of both nucleo...

Journal: :Chemical communications 2012
Babak Karimi Majid Vafaeezadeh

Incorporating a hydrophobic Brønsted acid ionic liquid (HBAIL) inside the nanospaces of SBA-15-Pr-SO(3)H led to a hydrophobic super Brønsted acid catalyst, which showed excellent catalytic performance in direct esterification of alcohols and carboxylic acids at ambient temperature under solvent-free conditions.

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