نتایج جستجو برای: shape selective catalysts
تعداد نتایج: 415754 فیلتر نتایج به سال:
Catalysts daily accelerate and boost thousands of different chemical reactions, and thereby form the basis for the multibillion dollar chemical industry worldwide and indispensable environmental protective technologies. Research in nanotechnology and nanoscience is expected to have a great impact on the development of new catalysts. The detailed understanding of chemistry of nanostructures and ...
The stereochemical divergent synthesis of indolyl-pyrrolidines was accomplished using an imidazoline-aminophenol (IAP)-Ni(OAc)2 complex and a bis(imidazolidine)pyridine (PyBidine)-Cu(OTf)2 complex. The former catalyzed exo'-selective asymmetric [3 + 2] cyclization of iminoesters with indolyl nitroalkenes, and the latter catalyzed the reaction in an endo-selective manner. These catalysts are tol...
The catalysts of iron-doped Mn-Ce/TiO2 (Fe-Mn-Ce/TiO2) prepared by sol-gel method were investigated for low temperature selective catalytic reduction (SCR) of NO with NH3. It was found that the NO conversion over Fe-Mn-Ce/TiO2 was obviously improved after iron doping compared with that over Mn-Ce/TiO2. Fe-Mn-Ce/TiO2 with the molar ratio of Fe/Ti = 0.1 exhibited the highest activity. The results...
Iron molybdate catalysts were prepared using a sol gel route with malonic acid and oxalic their performance for the selective oxidation of methanol to formaldehyde was evaluated.
Recent interest in the growth of aligned carbon nanotube films using transition metal catalysts has led to questions concerning the growth mechanism involved. In our experiment carbon tubules grown using Ni catalysts exhibit a preferred orientation relative to the catalytically active surfaces of Ni. The axial directions of the tubular structure are mainly parallel to the ^110& and ^042& direct...
Selective catalysts that activate small molecules such as hydrocarbons, dioxygen, water, carbon dioxide and dihydrogen are central to new technologies for the use of alternative energy sources. For example, controlled hydrocarbon functionalization can lead to high impact technologies, but such catalysts require a level of molecular control beyond current means. The Center for Catalytic Hydrocar...
Single-chamber fuel cells (SCFC) are ones in which the fuel and oxidizer are premixed, and selective electrode catalysts are used to generate the oxygen partial pressure gradient that in a conventional dual-chamber design is produced by physical separation of the fuel and oxidizer streams. SCFCs have been shown capable of generating power densities above 700 mW/cm with appropriate catalysts, ma...
E nzymes and other biocatalysts are increasingly important tools for synthesizing pharmaceuticals, improving diagnostic assays, enhancing efficiency of industrial processes, manufacturing biopolymers, accelerating bioremediation, and converting biomass to useful products and fuels. Although a variety of enzymes are available as reaction catalysts, their performance is often less than optimal fo...
The selective α,α-difluorination of carbonyl compounds remains a challenge in modern organic synthesis; current methods often incorporate stepwise processes and/or harsh conditions, providing unsatisfactory mixtures of mono- and difluorinated products. In this communication, a practical, mild, and one-pot method for the selective α,α-difluorination of readily available acid chlorides is reporte...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید