کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
209735 461681 2014 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Two-step synthesis of dimethyl carbonate from urea, ethylene glycol and methanol using acid–base bifunctional zinc-yttrium oxides
ترجمه فارسی عنوان
سنتز دو مرحله ای دی متیل کربنات از اوره، اتیلن گلیکول و متانول با استفاده از اکسید روی و اتیل بیوفناک
کلمات کلیدی
اوره، کربنات اتیلن، دی متیل کربنات، کاتالیزورهای بیفایزر اسید پایه
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
چکیده انگلیسی


• Zn/Y oxides with different precursors were prepared by co-precipitation method.
• The synthesis of DMC via a two-step process uses urea, EG and methanol.
• The catalyst with zinc nitrate precursor is highly active for the two processes.
• The acid-base bifunctional Zn/Y oxides greatly enhance catalytic activity.
• The interaction between Zn and Y oxides greatly enhance catalytic activity.

The binary zinc-yttrium oxides with different precursors were prepared by co-precipitation method and used in the catalytic synthesis of dimethyl carbonate (DMC) via a two-step process using urea, ethylene glycol and methanol as raw feed-stocks. The first step involves reaction of urea with ethylene glycol (EG) to form ethylene carbonate (EC), and 96% conversion of urea with 98% selectivity of EC was obtained. In the second step, namely transesterification of EC formed with methanol to give DMC and EG, the conversion of EC was up to 72% in 15 min with a 99% selectivity of DMC, corresponding to a TOF of 864 mmol/h gcat. XRD results showed that the catalyst with a zinc nitrate precursor has a remarkable interaction between zinc and yttrium oxides. TPD characterization indicated that in the catalyst with a zinc nitrate precursor there was a cooperative effect between weak acid and medium base sites on the surface of the catalyst, suggesting that the prepared catalysts are acid–base bifunctional. The synergistic effect between zinc and yttrium oxides, in combination with acidity of zinc oxide and basicity of yttrium oxide, may be responsible to the high catalytic activity and selectivity.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Fuel Processing Technology - Volume 126, October 2014, Pages 359–365
نویسندگان
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