Comparison of commercial solid acid catalysts for the esterification of acetic acid with butanol
Comparison of commercial solid acid catalysts for the esterification of acetic acid with butanol
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DOI：
10.1016/j.apcata.2005.09.006
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发表时间：
2006-01
影响因子：
5.5
通讯作者：
T. Peters;N. Benes;A. Holmen;J. Keurentjes
中科院分区：
文献类型：
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作者：
T. Peters;N. Benes;A. Holmen;J. Keurentjes
在非均相反应体系中，研究了不同固体酸催化剂对乙酸和丁醇酯化反应的影响。用均相催化剂硫酸、对甲苯磺酸和杂多酸进行了酯化对比实验。催化剂的特征在于使用气体吸附分析（BET），X-射线衍射（XRD），扫描电子显微镜（SEM）和程序升温分解（TPD）技术。非均相催化剂的活性按以下顺序降低：Smopex-101>Amberlyst 15>硫酸化ZrO 2>H-USY-20>H-BETA-12.5>H-MOR-45> Nb 2 O 5>H-ZSM-5-12.5。ZSM-5的低活性是该沸石型材料的中等尺寸孔中的内部扩散限制的结果。对于H-MOR，低活性可以通过一维H-MOR通道中的孔阻塞来解释。对于H-USY型分子筛，考察了Si/Al比对催化活性的影响。虽然酸中心的数量随着Si/Al比的增加而减少，但发现最佳的Si/Al比为20.硫酸化氧化锆的活性显示出最佳的煅烧温度，尽管酸中心的数量和酸度都随煅烧温度单调增加。最有可能的是，在较高的煅烧温度下，形成刘易斯酸位点，并去除布朗斯台德酸位点。由于布朗斯台德酸位点对于酯化反应的催化是必不可少的，这解释了活性的降低。
Esterification of acetic acid with butanol has been studied in a heterogeneous reaction system, using a variety of solid acid catalysts. Comparative esterification experiments have been carried out using the homogeneous catalysts sulphuric acid, p-toluenesulphuric acid and a heteropolyacid. The catalysts have been characterised using gas adsorption analysis (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM) and temperature-programmed decomposition (TPD) techniques. The weight-based activity of the heterogeneous catalysts decreases in the following order: Smopex-101>Amberlyst 15>sulphated ZrO2>H-USY-20>H-BETA-12.5>H-MOR-45>Nb2O5>H-ZSM-5-12.5. The low activity of ZSM-5 is a result of internal diffusion limitations in the medium sized pores of this zeolite type material. For H-MOR the low activity can be explained by pore blocking in the one-dimensional H-MOR channels. For the H-USY-type zeolites, the influence of the Si/Al ratio on catalytic activity has been examined. Although the amount of acid sites decreases with an increase in the Si/Al ratio, an optimum Si/Al ratio of 20 has been found. The activity of sulphated zirconia shows an optimum calcination temperature, even though both the amount and acidity of the acid sites increase monotonically with calcination temperature. Most likely, at higher calcination temperatures Lewis acid sites are formed and Brønsted acid sites are removed. As Brønsted acid sites are essential for catalysis of esterification reactions this explains the decrease in activity.