Promoting Effects of Anions on Hydrogen Storage Reactions of Li-N Based Materials

阴离子对Li-N基材料储氢反应的促进作用

• 批准号: 0931587
• 负责人: Yun Hu
• 金额: $ 30.27万
• 依托单位: Michigan Technological University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0931587&HistoricalAwards=false
• 关键词: Promoting; Effects; Anions; Hydrogen; Storage

0931587HuOne important material for hydrogen storage is lithium imide (Li2NH) because it can reversibly absorb as much as 6.5wt% hydrogen, via the reaction Li2NH + H2 = LiNH2 + LiH. However, its hydrogenation and dehydrogenation temperatures are currently too high, about 200C versus 80C required for transportation applications. The long term goal of this project is to develop high hydrogen storage capacity materials via doping Li2NH by anions. The PI hypothesizes that anions doping can be used to tune structures and properties of ionic compounds (Li2NH and LiNH2), which are key factors controlling hydrogen storage reactions. The PI bases his hypothesis on the observations that 1) anion/cation interactions dramatically affect catalyst performance, reaction kinetics, and reaction selectivity, 2) anion can selectively modify the properties of solid materials, 3) different Cl= containing promoters exhibit the same promoting effect on the dehydrogenation of LiNH2/LiH, which is clearly an indication of anion effects, and 4) Li2NH with O= ion showed much better hydrogen storage performance than that without O= ion. The specific aims of this experimental work are to: 1) correlate the effects of doping-anions on the hydrogen storage reactions of Li2NH with their intrinsic properties; 2) evaluate how anions doping affects the structures and properties of Li2NH and LiNH2; and 3) examine the effects of anions doping on the intermediate species of hydrogen storage reactions of Li2NH. This research has significant intellectual merit. Although metals and cations were widely used as promoters, anions have not yet been recognized as effective components to promote the hydrogen storage materials. Knowledge gained from this project on how anions doping affect the structures and properties of hydrogen storage materials could provide a new approach for developing new hydrogen storage materials. This project also has multiple broader impacts. The highly effective storage materials developed in this research can lead to low cost hydrogen storage materials which will impact the commercial feasibility of fuel cell vehicles, thus reducing the requirement of oil. This research has also strong impacts on the education of students. A "summer institute in hydrogen energy" program will be created. This program will promote the knowledge and skills of hydrogen energy science and engineering into the high school science classroom via training high school teachers. This project will train one graduate and one undergraduate student in this area. In addition, the PI is hoping to use this project to recruit under-represented (female) high school students as summer interns to his research group.

用于储氢的一种重要材料是亚胺锂（Li 2NH），因为它可以通过反应Li 2NH + H2 = LiNH 2 + LiH可逆地吸收多达6.5wt%的氢。 然而，其氢化和脱氢温度目前太高，约为200 ℃，而运输应用所需的温度为80 ℃。本项目的长期目标是通过阴离子掺杂Li 2NH来开发高储氢容量材料。PI假设阴离子掺杂可用于调节离子化合物（Li 2NH和LiNH 2）的结构和性质，这是控制储氢反应的关键因素。PI的假设基于以下观察结果：1）阴离子/阳离子相互作用显著影响催化剂性能、反应动力学和反应选择性，2）阴离子可以选择性地改变固体材料的性质，3）不同的含Cl=的促进剂对LiNH 2/LiH的脱氢表现出相同的促进作用，这清楚地表明了阴离子效应，含O=离子的Li_2NH比不含O=离子的Li_2NH具有更好的储氢性能。本实验工作的具体目的是：1）将掺杂阴离子对Li 2NH储氢反应的影响与其固有性质联系起来; 2）评估阴离子掺杂如何影响Li 2NH和LiNH 2的结构和性质; 3）检查阴离子掺杂对Li 2NH储氢反应中间产物的影响。这项研究具有重要的学术价值。虽然金属和阳离子被广泛用作促进剂，但阴离子尚未被认为是促进储氢材料的有效组分。从本项目中获得的关于阴离子掺杂如何影响储氢材料的结构和性能的知识可以为开发新的储氢材料提供新的方法。该项目还具有多个更广泛的影响。本研究开发的高效储氢材料可以产生低成本的储氢材料，这将影响燃料电池汽车的商业可行性，从而减少对石油的需求。这项研究对学生的教育也有很大的影响。将创建一个“氢能夏季研究所”项目。该计划将通过培训高中教师，促进氢能科学与工程的知识和技能进入高中科学课堂。该项目将在这一领域培训一名研究生和一名本科生。此外，PI希望利用这个项目招募代表性不足的（女性）高中生作为暑期实习生到他的研究小组。