نتایج جستجو برای: al mcm 41
تعداد نتایج: 528823 فیلتر نتایج به سال:
manganese (?) complex with 2, 2? bipyridine, 1, 1? dioxide (bpdo) ligand was immobilized within nanoreactors of mcm-41. the immobilized complex was characterized by powder x-ray diffraction (xrd), nitrogen adsorption desorption, and ftir. the pore volume, surface area and pore diameter of mcm-41 decreased after immobilization of mn complex. three bands observed at 1250, 1220 cm?1 and 757 cm?1 a...
In this study, an efficient and green process for the synthesis of dihydropyrimidin-2(1H)-ones from aromatic benzaldehydes, ethyl acetoacetate and urea using Al-MCM-41 as heterogeneous catalyst and microreactor under solvent-free conditions has been developed. The advantages of this method are easy work-up procedure, regeneration of the catalyst, clean and neutral reaction conditions.
In this study, an efficient and green process for the synthesis of dihydropyrimidin-2(1H)-ones from aromatic benzaldehydes, ethyl acetoacetate and urea using Al-MCM-41 as heterogeneous catalyst and microreactor under solvent-free conditions has been developed. The advantages of this method are easy work-up procedure, regeneration of the catalyst, clean and neutral reaction conditions.
Zeolite A and MCM-41 have extensive applications in basic science, petrochemical science, energy conservation/storage, medicine, chemical sensor, air purification, environmentally benign composite structure and waste remediation. However, the use of zeolite A and MCM-41 in these areas, especially environmental remediation, are restricted due to prohibitive production cost. Efficient recycling o...
Propylene is an important raw material for the production of many valuable compounds, especially polypropylene, consumption which continues to grow every year. The reaction oxidative dehydrogenation propane, where carbon dioxide used as a mild oxidant, promising method producing propylene. At same time, problem utilization greenhouse gas CO2 partially solved. synthesis and analysis physicochemi...
در این تحقیق، کاربرد دانش فناوری نانو برای حذف آنیون های نیترات از محلول آبی در سیستم پیوسته و ناپیوسته نشان داده شده است. با توجه به خطرات آلودگی آنیون های نیترات در محیط های آبی، استفاده از فرایند جذب سطحی توسط سیلیکاهای میان حفره عامل دار شده به عنوان روشی درمانی جهت حذف این آنیون حائز اهمیت می باشد. به این منظور ابتدا میان حفره mcm-41 سنتز شد و با استفاده از روش پیوند تکمیلی با گروه های عام...
نانو کامپوزیت ها با ماتریس مونت موریلونیت (mmt)، ag2co3-mmt w و ag2co3-mmt e در دو حلال آب و اتیلن گلیکول به طور جداگانه سنتز شدند. برای سنتز نانو کامپوزیت ag2co3-mcm-41 w تنها از حلال آب استفاده شد. فعالیت و پایداری نانو ذرات توسط ماتریس های طبیعی که به منظور تثبیت آنها استفاده شد، تحت تاثیر قرار گرفت. در پایان نامه حاضر دو ماتریس مونت موریلونیت (mmt) و ماده مزوپورmcm-41 برای ادغام با نانو ذرا...
al-mcm-41 nanoreactors is found to be a remarkable efficient catalyst for one-pot multicomponent cyclocondensation of benzil, aniline or ammonium acetate and aromatic aldehydes for the synthesis of polysubstituted imidazoles under solvent-free conditions. the reaction was efficiently promoted by 10 mg nano-al-mcm-41 and the heterogeneous catalyst was recycled for four runs in this reaction with...
Tetraethylenepentamine (TEPA)-based mesoporous MCM-41 is used as the adsorbent to determine the CO2 desorption kinetics of amine-modified materials after adsorption. The experimental data of CO2 desorption as a function of time are derived by zero-length column at different temperatures (35, 50, and 70 ◦C) and analyzed by Avrami’s fractional-order kinetic model. A new method is used to distingu...
Fe-substituted MCM-41 molecular sieves with ca. 1, 2, and 3 wt % Fe were synthesized hydrothermally using different sources of colloidal silica (HiSil and Cab-O-Sil) and characterized by ICP, XRD, N2 physisorption, UV-vis, EPR, TPR, and X-ray absorption. Catalysts synthesized from Cab-O-Sil showed higher structural order and stability than those from HiSil. The local environment of Fe in the me...
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