نتایج جستجو برای: various catalysts

تعداد نتایج: 797949  

The effects of potassium promoter for production of heavy hydrocarbons from syngas with silica- supported cobalt catalysts has been studied. After preparing the catalysts in accordance with the sol-gel method, they were subjected to various tests by using a small steely micro-reactor and capable of operating in diversified situations, such as stable temperature range, flow rate, space velocity,...

Journal: :international journal of advanced biological and biomedical research 2013
saman hajmohamadi saeedreza hajmohamadi

the objectives of this experiment were to investigate the application of new ligands including different atoms & evaluation their nucleophile effects against various metals. chemistry researchers are really interested in this field. from among various ligands, there are some ligands with different coordinating ligands as well. there are great number of intermediate complexes and major eleme...

2017
Seyed Mohsen Sadeghzadeh Mehdi Mogharabi

The reusability of valuable catalysts in organic reaction without change in properties is known as an important feature in the evolution of green processes. The imobiliza‐ tion of metal catalysts on magnetic nanoparticles makes them recoverable and can be used as building blocks for the fabrication of various functional systems, which are applied in several fields such as catalysis, environment...

2015
Mengshan Lee Rajender S. Varma

Chitosan, a bio-based polymer which has similar characteristics to those of cellulose, exhibits cationic behavior in acidic solutions and strong affinity for metals ions. Thus, it has received increased attention for the preparation of heterogeneous catalysts. Recent studies demonstrated that chitosan-based catalysts had high sorption capacities, chelating activities, stability and versatility,...

Journal: :Organic & biomolecular chemistry 2012
Zhi-Ming Zhou Zhi-Huai Li Xiao-Yan Hao Jun Zhang Xiao Dong Ying-Qiang Liu Wen-Wen Sun Dan Cao Jin-Liang Wang

Functional imidazolium ionic liquids have been developed as a new class of versatile catalysts. C(2)-symmetric imidazolium-tagged bis(oxazoline) ligands were prepared, and the anions of the ligands were altered. The catalysts based on the new ligands and Cu(OAc)(2)·H(2)O were applied in asymmetric Henry reactions between various aldehydes 3 and CH(3)NO(2)4. The catalysts achieved a high level o...

2001
R.H.H. Smits K. Seshan H. Leemreize

The influence of various preparation methods on the performance of V-Nb-0 catalysts has been investigated. It was found that the activity and selectivity of a vanadium site depend on the nature of the neighbouring atoms. Vanadium neighbours provide activity, while niobium neighbours provide selectivity. Careful preparation of these catalysts ensures a homogeneous distribution and good mixing of...

2006
Martin A. Abraham

Methanol, formaldehyde, carbon monoxide, and propylene conversion were examined in a laboratory flow reactor over three base-metal containing alumina-supported palladium (Pd) catalysts in addition to Pd on y-alumina catalyst. The base metals were cerium, barium, and a combination of the two. Experiments were performed to determine the effect of air to fuel ratio on lightoff temperatures of vari...

2015
Hyunah Kim Jimin Park Inchul Park Kyoungsuk Jin Sung Eun Jerng Sun Hee Kim Ki Tae Nam Kisuk Kang

The development of efficient and stable water oxidation catalysts is necessary for the realization of practically viable water-splitting systems. Although extensive studies have focused on the metal-oxide catalysts, the effect of metal coordination on the catalytic ability remains still elusive. Here we select four cobalt-based phosphate catalysts with various cobalt- and phosphate-group coordi...

Journal: :iranian journal of hydrogen & fuel cell 2015
nahid khandan mahmoud ziarati reza karkeabadi mohammad ali ghafouri roozbahani

steam reforming is one of the most important processes for producing hydrogen from hydrocarbon fuels such as lpg and has attracted much attention due to its high efficiency and economy. in this study, the lpg steam reforming reaction was investigated on nickel catalysts supported on four various zeolites (h-y, na-y, hzsm5 and ferrierite). the catalytic tests were performed in a tubular fixed be...

2010
Dingshan Yu Enoch Nagelli Feng Du Liming Dai

Many reactions involve metals, especially noble metals or metal oxides as catalysts. Although metal-based catalysts have been playing a major role in various industrial processes, they still suffer from multiple competitive disadvantages, including their high cost, susceptibility to gas poisoning, and detrimental effects on the environment. Owing to their wide availability, environmental accept...

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