Abstract

In the present work, mechanistic pathways and kinetics of catalytic dehydration of ethanol were investigated in a closed batch reactor for the formation of diethyl ether, and ethylene over the synthesized NiO loaded HZSM-5 in the range of 160–240 °C. The effect of the presence of water on reaction performance was also evaluated. No significant negative impact of water over diethyl ether yield was observed up to 1:1 ethanol–water molar ratio. The proposed two-step kinetic model highlights the mechanistically essential comparison between the strong (Brønsted) and weak (Lewis) acid sites of catalyst for ethanol conversion to diethyl ether. Intramolecular dehydration of ethanol over strong acid sites led to ethylene formation. Enhancement of weak acid sites due to NiO loading over HZSM-5 led to interestingly higher yields of diethyl ether by a combination of ethylene and ethanol. Optimal consideration for maximum conversions was observed with high reusability.

Graphic abstract

Graphical abstract for ethanol dehydration on Ni-HZSM-5 catalyst.

中文翻译：

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Ni-ZSM-5在封闭式间歇反应器中乙醇脱水成乙醚的动力学和机理研究

摘要

在目前的工作中，在密闭的间歇式反应器中研究了乙醇催化脱水的机理和动力学，该反应器用于在160–240°C的合成NiO负载的HZSM-5上形成乙醚和乙烯。还评估了水的存在对反应性能的影响。在乙醇与水的摩尔比为1：1的情况下，水对乙醚的收率没有明显的负面影响。拟议的两步动力学模型强调了将乙醇转化为乙醚的催化剂的强酸位点（布朗斯台德）和弱酸位点（刘易斯）之间在机理上的本质比较。乙醇在强酸位点上的分子内脱水导致形成乙烯。由于NiO负载在HZSM-5上而导致的弱酸位的增强，通过乙烯和乙醇的组合有趣地提高了乙醚的收率。观察到最大转换的最佳考虑，并具有高度可重用性。

图形摘要

Ni-HZSM-5催化剂上乙醇脱水的图形摘要。