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首页> 外文期刊>Journal of industrial and engineering chemistry >Investigation of different modifiers for nanocrystal zirconia on W/ZrO2 catalysts via esteriflcation
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Investigation of different modifiers for nanocrystal zirconia on W/ZrO2 catalysts via esteriflcation

机译：W / ZrO2催化剂上通过酯化作用研究纳米晶氧化锆的不同改性剂

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摘要

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 15wt% 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, esteriflcation 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.
机译：本工作着重研究钨改性的氧化锆催化剂上不同的改性剂，例如Si，Al，Bi和Pb。首先，将不同的改性剂前体引入摩尔比（金属：Zr）为0.01：1的纳米晶氧化锆上。然后，将15wt％的钨（W）浸渍到改性的氧化锆上。使用N2物理吸附，X射线衍射（XRD），扫描电子显微镜（SEM），能量色散X射线光谱（EDX）和电子自旋共振（ESR）来确定受改性剂影响的理化性质。为了测量催化活性，进行了乙酸和1-庚醇的酯化。已经发现，由于催化剂的酸性降低，改性剂显然导致活性大大降低。可以提出，修饰语具有三个主要作用： （i）抑制相变，（ii）增强F中心（在氧空位中稳定的电子）的存在，并且（iii）增加氧化锆上吸附物质的强相互作用。第三个效果是导致催化剂酸度显着降低的关键因素。

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