نتایج جستجو برای: heterogeneous catalyst
تعداد نتایج: 166602 فیلتر نتایج به سال:
in the present study, the effects of calcium doping on the performance of the co-precipitated cu-mgo catalysts prepared with different calcium loadings in the selective hydrogenation of furfuraldehyde were investigated. the results proved that the addition of this promoter had a remarkable impact on the catalytic performance. the conversion of furfuraldehyde enhanced up to 83% and the furfuryl ...
در این پروژه هدف اصلی انجام واکنش اکسایش اتیل بنزن و تولید استوفنون به عنوان محصول اصلی، با استفاده از کاتالیست ناهمگن بود در نتیجه بر آن شدیم کاتالیست ناهمگنی را بر پایه تثبیت پورفیرین بر روی سیلیکاژل طراحی کنیم. برای این منظور پورفیرینی را که دارای گروه عاملی استری بود به نام 5،10،15،20-تتراکیس (4-متوکسی کربونیل فنیل)پورفیرین را سنتز کرده و آن را با استفاده از واکنش تشکیل آمید بر روی سیلیکاژل...
In this study, the transesterification of palm oil with methanol for biodiesel production was studied by using CaO–ZnO as a heterogeneous base catalyst prepared by incipient-wetness impregnation (IWI) and co-precipitation (CP) methods. The reaction parameters considered were molar ratio of methanol to oil, amount of catalyst, reaction temperature, and reaction time. The optimum conditions—15:1 ...
a mild and green method has been developed for the preparation of coumarins derivatives through the one-pot reactions. in our study,various phenols and ethyl acetoacetate compound in which we used silica-supported boron sulfonic acid [sio2/b(so4h)3] as a new, highly efficient and tri-functional inorganic brønsted acid catalyst were processed under solvent-free condition and thermal. the catalys...
چکیده ندارد.
BACKGROUND Aryl sulfides have significant importance from biological and pharmaceutical aspects. Transition metal-catalyzed carbon-sulfur cross-coupling reaction represents an important tool for the synthesis of sulfides. Among various transition metals, copper salts or oxides have found vast applicability. RESULTS A simple procedure for the preparation of poly-ionic amberlite resins embedded...
Montmorillonite KSF has been used as an effective and non-toxic heterogeneous catalyst for one-pot synthesis of 5-substituted 1H-tetrazoles via [3+2] cycloaddition of sodium azide with a wide variety of nitriles. The reaction afforded high yields of the desired products in a short reaction time under mild reaction conditions. The catalyst can be recovered by simple filtration and reuse...
Present process of transesterification faces various challenges. The most challenging is to obtain high conversion rate when using high free fatty acid (FFA) feedstock. The aim of this study is to investigate transesterification process of rubber seed oil (RSO) through direct-ultrasonic irradiation (UI) with addition of waste material based heterogeneous catalyst. The waste material based heter...
polyethylene glycol was easily grafted to silica gel and used as a solid–liquid phase transfer catalyst in the reduction of aromatic nitro compounds. this silica-grafted polyethylene glycol is proved to be an efficient heterogeneous catalyst in the reduction of nitroarenes to the corresponding aromatic amines with zinc powder in water. the reduction reactions proceeded efficiently with excellen...
sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl]ester (saspspe) is employed as a recyclable catalyst for the silylation of hydroxyl groups. a good range of primary, secondary alcohols and phenolic hydroxyl groups were effectively converted into their corresponding trimethylsilyl ethers with hexamethyldisilazane in the presence of catalytic amounts of saspspe at room temperature with short rea...
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