کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
229185 464862 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Investigation of different modifiers for nanocrystal zirconia on W/ZrO2 catalysts via esterification
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Investigation of different modifiers for nanocrystal zirconia on W/ZrO2 catalysts via esterification
چکیده انگلیسی

The present work focused on investigation of different modifiers, such as Si, Al, Bi, and Pb on the tungstated zirconia catalysts. First, the different modifier precursors were introduced onto the nanocrystal zirconia having molar ratio (metal: Zr) at 0.01:1. Then, the 15 wt% of tungsten (W) was impregnated onto the modified zirconia. The physicochemical properties influenced by the modifiers were determined using the N2 physisorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and electron spin resonance (ESR). In order to measure the catalytic activity, esterification of acetic acid and 1-heptanol was performed. It was found that the modifiers apparently resulted in dramatically decreased activity due to decreased acidity of the catalysts. It can be proposed that the modifiers had three major roles; (i) inhibit the phase transformation, (ii) enhance the presence of F-center (electrons stabilized in oxygen vacancy), and (iii) increase strong interaction of adsorbed species on zirconia. The third effect was the key factor leading to pronounced decrease in acidity of the catalysts.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Industrial and Engineering Chemistry - Volume 16, Issue 6, 25 November 2010, Pages 935–940
نویسندگان
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