| 添加叔丁醇钾对Mg(NH2)2-2LiH体系储氢性能的影响 | |
| Effect of Potassium tert-Butoxide on Hydrogen Storage Properties of Mg(NH2)2-2LiH System | |
| 摘要: 叔丁醇钾（C4H9OK）的添加显著改善了Mg（NH2）2-2LiH体系的储氢性能。添加0.08 mol C4H9OK的Mg（NH2）2-2LiH-0.08C4H9OK样品表现出最佳储氢性能。该样品的起始放氢温度仅为70℃，较Mg（NH2）2-2LiH原始样品降低了60℃；130℃完全放氢后，该样品可在50℃开始吸氢，较原始样品降低了50℃。Mg（NH2）2-2LiH-0.08C4H9OK样品可在150℃的等温条件下50min内迅速放出质量分数3.82%的氢气，完全放氢后可在120℃的等温条件下50 min内快速吸收质量分数4.11%的氢气，表现出良好的吸放氢动力学性能。C4H9OK的添加降低了样品放氢反应的表观活化能和反应焓变，改善了放氢反应的动力学和热力学性能，从而降低了放氢反应温度。进一步的放氢反应机理研究发现，在180℃之前，C4H9OK对Mg（NH2）2-2LiH体系的放氢起催化改性作用；温度继续升高后，C4H9OK将会分解并参与放氢反应最终生成Li3K（NH2）4。 | |
| 关键词: 储氢材料 氨基物 叔丁醇钾 动力学 催化改性 反应机理 | |
| 基金项目: 国家自然科学基金（No.51501175）和浙江省杰出青年基金（No.LQ16E010001）资助。 | |
| Abstract: The hydrogen storage properties of Mg(NH2)2-2LiH system were significantly enhanced by adding a small amount of potassium tert-butoxide (C4H9OK). The 0.08 mol C4H9OK-added sample (Mg(NH2)2-2LiH-0.08C4H9OK) showed optimum hydrogen storage performances. The on-set dehydrogenation temperature of Mg(NH2)2-2LiH-0.08C4H9OK sample was only 70℃, which was 60℃ lower than that of pristine Mg(NH2)2-2LiH sample. After fully dehydrogenated at 130℃, the Mg(NH2)2-2LiH-0.08C4H9OK sample begined to absorb hydrogen at 50℃, which was 50℃ lower than the pristine sample. At 150℃, mass ratio of 3.82% of hydrogen can be rapidly released from the Mg(NH2)2-2LiH-0.08C4H9OK sample within 50 min. The fully dehydrogenated Mg(NH2)2-2LiH-0.08C4H9OK sample could absorb mass ratio of 4.11% hydrogen at 120℃ within 50 min. Adding C4H9OK decreases the dehydrogenation activation energy and reaction enthalpy of the Mg(NH2)2-2LiH system, and enhances the hydrogen desorption kinetic and thermodynamic properties. Mechanistic investigations indicate that C4H9OK acts catalytically to enhance the dehydrogenation properties before 180℃, then it participates in the reaction to generate Li3K(NH2)4 by further increasing the operating temperature. | |
| Keywords: hydrogen storage materials amide potassium tert-butoxide kinetics catalytic modification reaction mechanisms | |
| 投稿时间：2021-02-25 修订日期：2021-04-26 | |
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| 冯文钦,李超,刘凯元,蔡明源,范美强.添加叔丁醇钾对Mg(NH2)2-2LiH体系储氢性能的影响[J].无机化学学报,2021,37(6):1097-1105. | |
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