نتایج جستجو برای: heterogeneous catalytic

تعداد نتایج: 202404  

2016
Kapil Kandel Stacey Marie Althaus Takeshi Kobayashi Brian G. Trewyn Marek Pruski Igor I. Slowing Stacey M. Althaus Chorthip Peeraphatdit

The relative rates of the aldol reaction catalyzed by supported primary and secondary amines can be inverted by 2 orders of magnitude, depending on the use of hexane or water as a solvent. Our analyses suggest that this dramatic shift in the catalytic behavior of the supported amines does not involve differences in reaction mechanism, but is caused by activation of imine to enamine equilibria a...

Journal: :Organic & biomolecular chemistry 2016
Sofia M Bruno Ana C Gomes Tânia S M Oliveira Margarida M Antunes André D Lopes Anabela A Valente Isabel S Gonçalves Martyn Pillinger

Metal-free cucurbit[7]uril (CB7) solid-state assemblies promote acid-catalysed alcoholysis of aliphatic and aromatic epoxides under mild conditions to give β-alkoxy alcohols, which are important intermediates for the synthesis of a vast range of compounds such as bioactive pharmaceuticals. The catalytic process is heterogeneous and the catalyst can be reused in consecutive runs without any reac...

Journal: :Chemical Society reviews 2015
James Pritchard Georgy A Filonenko Robbert van Putten Emiel J M Hensen Evgeny A Pidko

The catalytic reduction of carboxylic acid derivatives has witnessed a rapid development in recent years. These reactions, involving molecular hydrogen as the reducing agent, can be promoted by heterogeneous and homogeneous catalysts. The milestone achievements and recent results by both approaches are discussed in this Review. In particular, we focus on the mechanistic aspects of the catalytic...

Journal: :Journal of the American Chemical Society 2010
Jun-Min Yan Xin-Bo Zhang Tomoki Akita Masatake Haruta Qiang Xu

Magnetically recyclable Au@Co core-shell nanoparticles were successfully synthesized in a one-step seeding-growth process within a few minutes. They were thermally stable and exhibited higher catalytic activity toward the dehydrogenation of ammonia borane than Au-Co alloy and the pure metal counterparts. This is a large enhancement in the catalytic activity of core-shell structured nanoparticle...

2011
Svetlana Ivanova Luis Francisco Bobadilla Anna Penkova Francisca Romero Sarria Miguel Angel Centeno Jose Antonio Odriozola

The present study tries to give an insight to the combination of the homogeneous and heterogeneous catalytic properties in a new class of materials. Well dispersed gold nanoparticles on an ionic liquid layer supported on a mineral carrier have been prepared. This work is concentrated on the characterizations and understanding of the interactions between all the components of the catalytic syste...

2017
Carmen Moreno-Marrodan Francesca Liguori Pierluigi Barbaro

The catalytic partial hydrogenation of substituted alkynes to alkenes is a process of high importance in the manufacture of several market chemicals. The present paper shortly reviews the heterogeneous catalytic systems engineered for this reaction under continuous flow and in the liquid phase. The main contributions appeared in the literature from 1997 up to August 2016 are discussed in terms ...

2014
Soe Lwin Israel E. Wachs

The literature of olefin metathesis by heterogeneous supported catalysts, both industrial-type supported metal oxides (ReOx/Al2O3, ReOx/(SiO2−Al2O3), MoOx/SiO2, MoOx/Al2O3, MoOx/(SiO2−Al2O3), WOx/SiO2, and WOx/ (SiO2−Al2O3)) and supported organometallic complexes, is comprehensively reviewed. The focus of this Review is supported metal oxide catalysts, but the well-defined supported organometal...

Journal: :chemistry of solid materials 2015
m. ali nia asli m. a. rezvani m. oveisi l. abdollahi

transition-metal-substituted  (tms)  polyoxometalates  of  the  general  formula  [siw9m3o39], (where m = first row transition metal), has been synthesized and supported on anatase by sol–gel method under oil-bath condition. the tetrabutylammonium (tba) salts of the keggin-type polyoxotungstates  [siw9m3o39],  (m = vii, crii, mnii,  feii coii  and niii),  proved  to  be  green, reusable,  and  ...

Journal: :Chemical communications 2011
Hyun Chul Cho Han Sol Lee Jiseul Chun Sang Moon Lee Hae Jin Kim Seung Uk Son

Tubular microporous organic networks bearing imidazolium salts (T-IM) were prepared by Sonogashira coupling of tetrakis(4-ethynylphenyl)methane and diiodoimidazolium salts, which showed promising catalytic activities in heterogeneous conversion of CO(2) into cyclic carbonates.

Journal: :Dalton transactions 2016
A W Augustyniak W Zawartka J A R Navarro A M Trzeciak

Methanolic reduction of [PdCl2(CH3CN)2] on a [Ni(2,5-di(1H-pyrazol-4-yl)benzenesulfonate)2] metal organic framework gives rise to Pd(2+)/Pd(0) nanocomposites with Suzuki and carbonylative Suzuki heterogeneous catalytic activities.

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید