نتایج جستجو برای: catalyst characterization

تعداد نتایج: 415808  

2013
Wenjin Yan Xinli Jia Tao Chen Yanhui Yang

In our former work [Catal. Today 174 (2011) 127], 12 heterogeneous catalysts were screened for CO oxidation, and Au-ZnO/Al2O3 was chosen and optimized in terms of weight loading of Au and ZnO. The present study follows on to consider the impact of process parameters (catalyst preparation and reaction conditions), in conjunction with catalyst composition (weight loading of Au and ZnO, and total ...

Journal: :Journal of microscopy 2006
J B Wagner N D Othman D S Su S B A Hamid R Schlögl

High-resolution transmission electron microscopy characterization of molybdenum oxide catalyst precursors is carried out for a better understanding of the mechanisms leading to the active catalytic material. The precipitated material consists of both large-unit cell crystals and randomly orientated clusters on a 3-5 nm scale. The crystalline clusters are embedded in non-crystalline material, pr...

H3PW12O40 (PW12) was immobilized over mesoporous alumina through the reaction of mesoporous alumina functionalized 3-aminopropyl triethoxy silane (3-APTES) and PW12. The surface properties of the functionalized nanocomposite was analyzed by a series of characterization techniques like elemental analysis, FTIR and XRD. XRD and adsorption–desorption analysis shows that the mesostructure of silica...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2013
ali fazeli abbas ali khodadadi yadollah mortazavi, hossein manafi

hydrogen can be produced for fuel cell applications by using methanol steam reforming reaction. in this article, a method was developed for regeneration of accelerated deactivated methanol-steam-reforming catalyst. successive deactivation–regeneration cycles were studied in a 250 hours test for the first time including 6 regeneration cycles. it is shown that regeneration of the catalyst in dilu...

2010
A. A. Refaat

Biodiesel production is worthy of continued study and optimization of production procedures due to its environmentally beneficial attributes and its renewable nature. Heterogeneous transesterification is considered to be a green process. The process requires neither catalyst recovery nor aqueous treatment steps and very high yields of methyl esters can be obtained, close to the theoretical valu...

ژورنال: مواد پرانرژی 2016

1,1-Dimethylhydrazine (UDMH) is used as a liquid fuel for missile and is a toxic matter. In this work to decontaminate UDMH from aqueous solution, hybridized photocatalytic and hydrogen peroxide oxidation processes have been used. The process was performed in a suspension reactor equipped with a UV-C lamp (150 W). Fe3O4@SiO2@TiO2 (FST) catalyst was used as a magnetic recyclable photocatalyst. T...

2017
Jordi Van Loon Kris P. F. Janssen Thomas Franklin Alexey V. Kubarev Julian A. Steele Elke Debroye Eric Breynaert Johan A. Martens Maarten B. J. Roeffaers

The performance of zeolites as solid acid catalysts is strongly influenced by the accessibility of active sites. However, synthetic zeolites typically grow as complex aggregates of small nanocrystallites rather than perfect single crystals. The structural complexity must therefore play a decisive role in zeolite catalyst applicability. Traditional tools for the characterization of heterogeneous...

Journal: :Dalton transactions 2015
Julianne M Thomsen Daria L Huang Robert H Crabtree Gary W Brudvig

Organometallic Ir precatalysts have been found to yield homogeneous Ir-based water-oxidation catalysts (WOCs) with very high activity. The Cp*Ir catalyst series can operate under a variety of regimes: it can either act as a homogeneous or a heterogeneous catalyst; it can be driven by chemical, photochemical, or electrochemical methods; and the molecular catalyst can either act in solution or su...

Journal: :Dalton transactions 2010
Claudine Rangheard César de Julián Fernández Pim-Huat Phua Johan Hoorn Laurent Lefort Johannes G de Vries

The use of non-supported Fe nanoparticles in the hydrogenation of unsaturated C-C bonds is a green catalytic concept at the frontier between homogeneous and heterogeneous catalysis. Iron nanoparticles can be obtained by reducing Fe salts with strong reductants in various solvents. FeCl(3) reduced by 3 equivalents of EtMgCl forms an active catalyst for the hydrogenation of a range of olefins and...

Journal: :Nanoscale 2011
Haiyan Wang Dayong Wu Dongzhou Li Zhongwei Niu Yuzhe Chen Daihua Tang Min Wu Jianhua Cao Yong Huang

A core/sheath structured mesoporous silica nanofibre was prepared by coaxial electrospinning combined with the solvent evaporation induced surfactant assembly process. The characterization has given convincing evidence for the continuous highly ordered mesoporous structures, and its catalyst application was tested.

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