کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
39599 45828 2014 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Vanadium phosphorus oxide catalyst promoted by cobalt doping for mild oxidation of benzyl alcohol to benzaldehyde in the liquid phase
ترجمه فارسی عنوان
کاتالیست اکسید فسفات وانادیوم توسط دوپینگ کبالت برای اکسیداسیون بنزیل الکل به بنزالدئید در فاز مایع
کلمات کلیدی
وانادیل پیرو فسفات، سازنده، شرکت، اکسیداسیون بنزیل الکل
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
چکیده انگلیسی


• VPO-Co catalysts with different Co/V molar ratios prepared by classical organic method.
• Oxidation of alcohols was studied in the liquid phase over VPO-Co catalyst.
• VPO-Co catalyst had excellent activity for alcohol oxidation.
• Effects of substrates, temperature, catalyst amount and solvents were investigated.
• The selected catalyst was reused without significant loss of activity.

A series of cobalt-doped vanadium phosphorus oxides (VPO-Co) catalysts, as well as unpromoted sample (VPO) were prepared using classical organic method via VOHPO4·0.5H2O precursor followed by calcinations in n-butane/air environment at 400 °C for 24 h. Techniques such as XRD, BET surface area, chemical titration, SEM, TPR and FT-IR were used for characterization of the catalysts. The results showed that promoted and unpromoted VPO catalyst were contained crystalline form of V4+ (vanadyl pyrophosphate, (VO)2P2O7) and also a small amount of V5+ (β-VOPO4 phase). However, Co promoted VPO contained poorer crystallinity compared to the unpromoted catalysts. CoPO4 phase also observed in the VPO-Co series and the intensities of the X-ray lines of CoPO4 increased with the increase of the Co/V molar ratio. In addition, the promotion of Co resulted in larger amount of V5+ species. Co was found to increase the average oxidation number of vanadium from 4.28 to 4.35 due to an addition of V5+ oxidation state from 28% to 35%.Oxidation of benzyl alcohol, for the first time, was studied in the liquid phase over VPO and VPO-Co catalysts, using tert-butylhydroperoxide (TBHP) as an oxidant. The catalytic tests showed that cobalt doping significantly increased the overall activity for the oxidation of benzyl alcohol. At 90 °C, the obtained activities were 0.662 and 1.014 gpro g−1VPO h−1 over the VPO and VPO-Co (molar ratio Co/V = 0.01) catalysts, respectively. The effects of reaction temperature, amount of the catalyst, solvents, and catalyst recycling of VPO-Co in liquid phase were also investigated.

Oxidation of benzyl alcohol is studied in the liquid phase over cobalt-doped vanadium phosphorus oxide (VPO-Co) catalyst using tert-butylhydroperoxide (TBHP). The activity of VPO-Co samples was considerably increased with respect to VPO catalyst and these samples are found to be suitable for the selective oxidation of alcohols.Figure optionsDownload high-quality image (105 K)Download as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Catalysis A: General - Volume 482, 22 July 2014, Pages 189–197
نویسندگان
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