Isomerisation of n-hexane over sulphated zirconia modified by noble metals
Isomerisation of n-hexane over sulphated zirconia modified by noble metals
复制标题
DOI：
10.1016/j.apcata.2005.10.045
复制
发表时间：
2006-01
影响因子：
5.5
通讯作者：
T. Løften;E. Blekkan
中科院分区：
文献类型：
--
作者：
T. Løften;E. Blekkan
在工业条件下，研究了Pt、Rh、Ir和Ru促进的硫酸化氧化锆催化正己烷异构化反应。Pt促进的样品显示出最高的活性，并且它比商业的基于沸石的催化剂活性高得多。用铑和铱促进的样品显示出较低且相似的活性，而钌效率较低且得到较不稳定的催化剂。所有样品的选择性相似，甲基戊烷和2，3-二甲基丁烷作为主要和初级产物。反应动力学参数符合双功能机理：正己烷中为正序反应，氢气中为负序反应，反应活化能约为90 kJ/mol。样品的预还原是实现高活性所必需的，但是如果活化温度过高，则活性丧失，这可能是由于通过过度还原而丧失硫酸根基团。
Isomerisation of n-hexane has been studied at industrially relevant conditions over sulphated zirconia promoted with Pt, Rh, Ir, and Ru. The Pt-promoted sample showed the highest activity, and it was considerably more active than a commercial, zeolite-based catalyst. The samples promoted with rhodium and iridium showed a lower, and similar activity, while ruthenium was less efficient and gave a less stable catalyst. The selectivities were similar for all the samples, with the methylpentanes and 2,3-dimethylbutane as main and primary products. Measured kinetic parameters for the reaction were in agreement with a conventional bifunctional mechanism: Positive order in n-hexane, negative in hydrogen and an activation energy around 90kJ/mol. Prereduction of the samples was necessary to achieve a high activity, but if the activation temperature was too high the activity was lost, probably due to the loss of sulphate groups through excessive reduction.