تحميل البيلون بأكسيد التنغستين ودراسة خواصه الفيزيوكيميائية

الموضوعات

علوم بحتة وطبيعية

روابط وملفات

التعريف والنوع

رقم الوثيقة

ee42bac6-e37f-494d-9a6b-ef8f7bba29ea

رقم العقد

0

نوع الوسائط

Crawler

نوع المحتوى

الرسائل العلمية

صيغة المصدر

رسائل ماجيستير

نوع الملف

pdf text

أسماء الملفات

1959671_1.pdf

بيانات النشر

ترجمة العنوان

LOADING OF CLAY WITH TUNGSTEN OXID AND STUDYING SOME OF ITS PHYSIOCHEMICAL PROPERTIES

ألقاب المؤلفين

[{"name_ar":"رهف أشرم","title_ar":"اعداد","title_en":"Preparation"},{"name_ar":"ماهر كرمان","title_ar":"اشراف","title_en":"Supervision"}]

اللغة

Arabic

المصدر والدورية

اسم المصدر

تحميل البيلون بأكسيد التنغستين ودراسة خواصه الفيزيوكيميائية

المحتوى والصفحات

عدد الصفحات

0

ترجمة الملخص

Catalysts :Samples of Clay-WO3catalysts were prepared by mechanical mixing method, The samples dried at 120oC, then calcined at 500 oC for 5 h .The samples contain: Number of sample Samples WO3wt.%B wt.%10.1-3WO-B0.199.9250.-3WO-B0.599.531-3WO-B19945 -3WO-B595501-3WO-B1090620-3WO-B2080735-3WO-B3565850-3WO-B50509B01002-Techniques:The FT-IR spectra recorded in FT-IR spectrometer (Jasco , model 4100) . The samples pressed into discs (by mixing 0.005 g of the sample with 0.2 g KBr in 13 mm disc diameter) and placed in an IR cell. Then, the spectra ).1-1200 cm-recorded in the range (400The total acidity of the prepared catalysts was measured by means of Potentiometric titration. Thesolid (0.2 g) was suspended in 20 ml acetonitrile (Merck) and agitated for 3 h. Then, the suspension was titrated with (0.005 M) n-butylamine in acetonitrile at 0.05 ml/min. The electrode potential variation was measured by potentiometric titration instrument (Metrohm) using a pH electrode (model 6.0229.100).The type of acid sites (Brønsted and/or Lewis) presented on the surface was determined with a Faurier transform infrared spectrometer (FTIR) by C under vacuum odegassed at 200 . The samplesmeans of pyridine adsorptionTorr) for 3 h. After cooling to room temperature, 1 ml of pyridine (Merek) 4-(10was added to each catalyst (0.5 g) and kept at room temperature for a week, C othen, the excess pyridine was removed and the catalysts dried at 100 overnight. The samples were pressed into discs (by mixing 0.005 g of the sample with 0.2 g KBr in 13 mm disc diameter) and placed in IR cell. Then, FT/IR spectra of pyridine adsorbed on the samples were recorded in the range by using FT/IR spectrometer (Jasco, 4100 model).1-1650 cm-of : 1400The surface areas of the clay-WO3catalysts were determined by adsorption of MB from organic solution by adding 0.1g of every sample to 25ml of the respective organic solution at a given initial concentration (C0) , and shaking for 72 h. the equilibrium concentration (Ce) was determined using Jasco spectrophotometer at the appropriate wavelengths .The catalytic activity of prepared catalysts was tested by conversion of isopropanol. The reaction of conversion was carried out in a continuous-flow system with fixed bed Pyrex reactor at atmospheric pressure. A vapor-phase mixture (alcohol/air =10/100) was fed on 3 cm3of the catalyst at flow rate of 110 ml/min. The temperature of the catalyst was measured by a K-type thermocouple positional in such a way that it touched the surface of the catalyst bed. In order to eliminate the catalytic effect of the thermocouple, the thermocouple tightly inserted in a thin wall Pyrex glass tube. A temperature range from 150 oC to 250oC with a 25 oC increment was used to evaluate the catalytic activity and selectivity of the catalysts. The reaction products were analyzed by a gas chromatography (Agilent Technologies-7890A) equipped with both FID and TCD detectors by using a column, 30 m long (DB Wax model).3-Results:The results show the following points:The FT/ IR spectra of the all prepared samples show characteristic bonds which assign to presence of WO3and show peaks due to the vibration of Si-O and Si-O-Si.The surface areas of the all prepared samples were determined by adsorption of MB from aqueous solution and were found(100-411 m2/g) in case of catalysts calcined at 500oC.The PH values of the surface of the prepared samples were found (6.30-7.90) .The surface acidity measurement reveal that the sites of all samples in are very strong (261 mV≤Ei≤105.6 mV)which shows less to talacid amount and shows increase strong acidic sites with adding WO3. The FT-IR spectra of pyridine adsorbed on the prepared samples show the characteristic vibration bands of pyridine adsorbed on the both Lewis and Brønsted .Results of the catalytic activity reveal that conversion of isopropanol over the all catalysts proceed dehydration reactions (producing propene) The all prepared catalysts were very active for the dehydration process of isopropanol.The Eavalues for conversion of is opropanolover the prepared catalysts were in the range(45.761-79.939 kJ/mol

إشراف وإعداد

الإشراف

ماهر كرمان

الإعداد

رهف أشرم

الاقتباسات الببليوغرافية