نتایج جستجو برای: Hybrid catalysts

تعداد نتایج: 223194  

Journal: :polyolefins journal 2015
gholam-reza nejabat mehdi nekoomanesh hassan arabi hamid salehi-mobarakeh gholam-hossein zohuri

several types of hybrid catalysts are made through mixing of 4th generation ziegler-natta (zn) and (2-phind)2zrcl2metallocene catalysts using triethylaluminum (tea) as coupling agent. response surface methodology (rsm)is used to evaluate the interactive effects of different parameters including amounts of metallocene and tea andtemperature on metallocene loading. analyzing the amounts of al and...

Journal: Polyolefins Journal 2015

Several types of hybrid catalysts are made through mixing of 4th generation Ziegler-Natta (ZN) and (2-PhInd)2ZrCl2  metallocene catalysts using triethylaluminum (TEA) as coupling agent. Response surface methodology (RSM) is used to evaluate the interactive effects of different parameters including amounts of metallocene and TEA and temperature on metallocene loading. Analyzing the amounts of Al...

2008
Hyunwoong Park Wonyong Choi Michael R. Hoffmann

A variety of combinations of CdS, TiO2, and Pt in preparing the hybrid catalysts were studied for hydrogen production under visible light (l > 420 nm) irradiation. The preparation method sensitively influenced the activity of the ternary hybrid catalysts. The formation of the potential gradient at the interface between CdS and TiO2 is necessary in achieving the efficient charge separation and t...

Journal: :Dalton transactions 2014
C C Gheorghiu B F Machado C Salinas-Martínez de Lecea M Gouygou M C Román-Martínez P Serp

Chiral rhodium hybrid nanocatalysts have been prepared by covalent anchorage of pyrrolidine-based diphosphine ligands onto functionalized CNTs. This work constitutes the first attempt at covalent anchoring of homogeneous chiral catalysts on CNTs. The catalysts, prepared with two different chiral phosphines, were characterized by ICP, XPS, N2 adsorption and TEM, and have been tested in the asymm...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - پژوهشکده علوم 1388

heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...

Journal: :Journal of the American Chemical Society 2014
Yu Bai Wenhua Zhang Zhenhua Zhang Jie Zhou Xijun Wang Chengming Wang Weixin Huang Jun Jiang Yujie Xiong

Heterogeneous catalysis often involves charge transfer from catalyst surface to adsorbed molecules, whose activity thus depends on the surface charge density of catalysts. Here, we demonstrate a unique solution-phase approach to achieve controllable interfacial lengths in oxide-metal hybrid structures. Resulting from their different work functions, surface polarization is induced by the Ag-CuO ...

Journal: :Chemistry 2007
Lei Zhang Hendrikus C L Abbenhuis Gijsbert Gerritsen Nollaig Ní Bhriain Pieter C M M Magusin Brahim Mezari Wei Han Rutger A van Santen Qihua Yang Can Li

A novel interfacial hybrid epoxidation catalyst was designed with a new immobilization method for homogeneous catalysts by coating an inorganic support with an organic polymer film containing active sites. The titanium silsesquioxane (TiPOSS) complex, which contains a single-site titanium active center, was immobilized successfully by in-situ copolymerization on a mesoporous SBA-15-supported po...

2007
M. Grzesik A. Ptaszek J. Skrzypek P. Ptaszek

This work includes a modelling and simulation of dimethyl ether direct synthesis in a tubular type reactor with hybrid catalysts bed. The results of simulation show that the loading ratio of methanol synthesis and dehydration catalysts has a important influence on product yield.

Journal: :Dalton transactions 2015
Xu Zhou Fei Li Xiaona Li Hua Li Yong Wang Licheng Sun

Photocatalytic oxidation of organic compounds proceeded efficiently in a hybrid system with ruthenium aqua complexes as catalysts, BiVO4 as a light absorber, [Co(NH3)5Cl](2+) as a sacrificial electron acceptor and water as an oxygen source. The photogenerated holes in the semiconductor are used to oxidize molecular catalysts into the high-valent Ru(IV)=O intermediates for 2e(-) oxidation.

Journal: :Nature materials 2011
Yongye Liang Yanguang Li Hailiang Wang Jigang Zhou Jian Wang Tom Regier Hongjie Dai

Catalysts for oxygen reduction and evolution reactions are at the heart of key renewable-energy technologies including fuel cells and water splitting. Despite tremendous efforts, developing oxygen electrode catalysts with high activity at low cost remains a great challenge. Here, we report a hybrid material consisting of Co₃O₄ nanocrystals grown on reduced graphene oxide as a high-performance b...

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