نتایج جستجو برای: nanoporous solid acid catalyst

تعداد نتایج: 961401  

Journal: :Journal of the American Chemical Society 2008
Karl D Hammond Fulya Dogan Geoffrey A Tompsett Vishal Agarwal W Curtis Conner Clare P Grey Scott M Auerbach

Nanoporous acid catalysts such as zeolites form the backbone of catalytic technologies for refining petroleum. With the promise of a biomass economy, new catalyst systems will have to be discovered, making shape-selective base catalysts especially important because of the high oxygen content in biomass-derived feedstocks. Strongly basic zeolites are attractive candidates, but such materials are...

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...

2013
Yao-Bing Huang Yao Fu

As the main component of lignocelluloses, cellulose is a biopolymer consisting of many glucose units connected through β-1,4-glycosidic bonds. Breakage of the β-1,4-glycosidic bonds by acids leads to the hydrolysis of cellulose polymers, resulting in the sugar molecule glucose or oligosaccharides. Mineral acids, such as HCl and H2SO4, have been used in the hydrolysis of cellulose. However, they...

2013
Hossein Naeimi Zahra Sadat Nazifi

ABSTRACT The functionalization of silica-coated Fe3O4 magnetic nanoparticles (Fe3O4@SiO2) using chlorosulfonic acid were afforded sulfonic acid-functionalized magnetic Fe3O4 nanoparticles (Fe3O4@SiO2-SO3H) that can be applied as an organic-inorganic hybrid heterogeneous catalyst. The used Fe3O4 magnetic nanoparticles are 18-30 nm sized that was rapidly functionalized and can be used as catalyst...

Journal: :Chemical communications 2015
Shengzong Liang Gerald B Hammond Bo Xu

The combined acid catalyzed hydration of alkynes is an efficient one-step synthesis of carbonyl compounds. This atom-economical method is effective with a wide range of substrates, and the products are obtained in very good yields with low catalyst loading (0.2%). Furthermore, solid acids like Nafion were also efficient and could be easily recycled multiple times without loss of reactivity.

2005
Heiner Lieske

In contrast to solid acid catalysts, much fewer efforts have been made to study solid base catalysts. In this thesis, preparation, characterization and application of oxides and modified oxide as solid base catalysts were studied. The catalysts include MgO prepared by different methods, potassium-modified ZrO2, calcined Mg-Al hydrotalcites, and a novel catalyst system Mg(O,F), which was prepare...

Journal: :Chemical communications 2010
Jifeng Pang Aiqin Wang Mingyuan Zheng Tao Zhang

The hydrolysis of cellulose over sulfonated carbons was promoted greatly by elevating the sulfonation temperature. With 250 degrees C-sulfonated CMK-3 as a catalyst, the cellulose was selectively hydrolyzed into glucose with the glucose yield as high as 74.5%, which is the highest level reported so far on solid acid catalysts.

Journal: :International Journal of Technology: IJ Tech 2023

This study utilizes ZrO2/Bagasse Fly Ash as a solid catalyst to convert Free Fatty Acid (FFA) from Palm Distillate (PFAD) into biodiesel. The fly ash was characterized by several physicochemical techniques, i.e., N

Journal: :iranian journal of catalysis 2015
ghodsi mohammadi ziarani zeinab aslani shima asadi

bis(indolyl)methanes are important group of bioactive metabolites of terrestrial and marine regions. they were synthesized by different methods. herein, a clean, one-pot synthesis of bis(indolyl)methane derivatives by cyclo-condensation reaction of indole and various aldehydes using sulfonic acid functionalized silica (sio2-pr-so3h) in aqueous media is reported. the advantages of this new metho...

2010
Hee Dong Jang Hankwon Chang Kuk Cho Franklin Kim Kwonnam Sohn Jiaxing Huang

Nanoporous Pt/TiO2 micro-particles were synthesized via an aerosol assisted co-assembly (AACA) route. Aerosol droplets were produced from a colloidal mixture of 5 nm Pt and 20 nm TiO2 nanoparticles, which formed spherical micro-aggregates of Pt and TiO2 with average diameter of around 1.2 μm. The resulting composite micro-particles have very open structure with pore sizes ranging from 20 to 200...

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