Ring opening of decalin and tetralin on HY and Pt/HY zeolite catalysts
Ring opening of decalin and tetralin on HY and Pt/HY zeolite catalysts
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DOI：
10.1016/j.jcat.2004.08.030
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发表时间：
2004-11
影响因子：
7.3
通讯作者：
M. Santikunaporn;J. Herrera;S. Jongpatiwut;D. Resasco;W. Alvarez;E. L. Sughrue
中科院分区：
文献类型：
--
作者：
M. Santikunaporn;J. Herrera;S. Jongpatiwut;D. Resasco;W. Alvarez;E. L. Sughrue
为了响应日益严格的环境法规，从柴油燃料中去除多核芳烃激发了大量的研究。除了使芳族化合物饱和的氢化反应之外，一个令人感兴趣的可能性是由芳族化合物饱和衍生的环烷环的开环以产生更高十六烷值的分子。在这方面的贡献，我们已经调查了一系列的HY和Pt/HY催化剂不同的酸性密度。在本实验条件下，这些催化剂上主要发生缩环和开环反应。尽管来自这些反应的产物的十六烷值不显著高于饱和芳族化合物的十六烷值，但它们可以是高十六烷值化合物如正链烷烃和一些异链烷烃的重要中间体。本研究的结果表明，HY沸石可以是有效的催化剂，为十氢萘的缩环和开环，如果它们的酸性密度调节到一个中间的最佳值，即，足够高，以实现转化，但不太高，将导致快速失活。在产物中获得的低顺反比是由于顺反异构化，但更重要的是，顺式-十氢萘的反应性比反式-十氢萘高得多。此外，顺式-十氢化萘比反式-十氢化萘更有选择性地转化为开环产物，反式-十氢化萘主要转化为裂解产物。由于四氢萘加氢生成十氢萘，在Pt存在下，四氢萘缩环和开环产物的产生大大增强。在氢气存在下，Pt/HY催化剂以及HY和Pt的物理混合物比HY催化剂有效得多。
The removal of polynuclear aromatics from diesel fuel in response to increasingly stringent environmental legislation has stimulated intense research. In addition to the hydrogenation reaction that saturates aromatics, an interesting possibility is the opening of naphthenic rings derived from the saturation of aromatics to produce molecules of higher cetane numbers. In this contribution, we have investigated a series of HY and Pt/HY catalysts of varying acidity densities. Under the conditions of this study, mainly ring-contraction and one-ring opening reactions take place over these catalysts. Although the products from these reactions do not have cetane numbers significantly higher than those of the saturated aromatics, they can be important intermediates to high cetane number compounds, such as normal paraffins and some iso-paraffins. The results of this investigation show that HY zeolites can be effective catalysts for the ring contraction and one-ring opening of decalin if their acidity density is adjusted to an intermediate optimum, that is, high enough to achieve conversion, but not too high that would result in fast deactivation. The low cis-to-trans ratios obtained in the products are due both to the cis-to-trans isomerization, but more importantly, to a much higher reactivity of cis-decalin than trans-decalin. Also, cis-decalin converts much more selectively to ring-opening products than trans-decalin, which mainly converts to cracking products. The production of ring-contraction and ring-opening products from tetralin is greatly enhanced in the presence of Pt due to hydrogenation of tetralin to decalin. In the presence of hydrogen Pt/HY catalysts as well as physical mixtures of HY and Pt are much more effective than HY catalysts.