Carbon Dioxide Capture by an Amine Functionalized Ionic Liquid: Fundamental Differences of Surface and Bulk Behavior
Carbon Dioxide Capture by an Amine Functionalized Ionic Liquid: Fundamental Differences of Surface and Bulk Behavior
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DOI：
10.1021/ja410745a
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发表时间：
2014-01-08
影响因子：
15
通讯作者：
Maier, Florian
中科院分区：
文献类型：
--
作者：
Niedermaier, Inga;Bahlmann, Matthias;Maier, Florian
采用表面和体敏实验技术研究了310 K下胺功能化离子液体（IL）二羟乙基二甲基牛磺酸铵对二氧化碳（CO2）的吸收。从在0.9毫巴CO2下的近环境压力X射线光电子能谱，在近表面区域中每摩尔IL捕获的CO2的量被量化为类似于0.58摩尔，其中类似于0.15摩尔的氨基甲酸酯二价阴离子形式和类似于0.43摩尔的氨基甲酸形式。从等温吸收实验结合红外光谱，CO2被发现结合在散装氨基甲酸酯（与标称0.5摩尔的CO2结合每1摩尔的IL）高达类似于2.5巴CO2，并作为氨基甲酸（与标称1摩尔CO2结合每1摩尔IL）在较高的压力。我们的属性的事实，在低压下氨基甲酸是在近表面区域的主要物种，而只有氨基甲酸酯形成的散装，溶剂化的最外层IL层相比，散装的情况下的差异。
Carbon dioxide (CO2) absorption by the amine-functionalized ionic liquid (IL) dihydroxyethyl dimethylammonium taurinate at 310 K was studied using surface- and bulk-sensitive experimental techniques. From near-ambient pressure X-ray photoelectron spectroscopy at 0.9 mbar CO2, the amount of captured CO2 per mole of IL in the near-surface region is quantified to similar to 0.58 mol, with similar to 0.15 mol in form of carbamate dianions and similar to 0.43 mol in form of carbamic acid. From isothermal uptake experiments combined with infrared spectroscopy, CO2 is found to be bound in the bulk as carbamate (with nominally 0.5 mol of CO2 bound per 1 mol of IL) up to similar to 2.5 bar CO2, and as carbamic acid (with nominally 1 mol CO2 bound per 1 mol IL) at higher pressures. We attribute the fact that at low pressures carbamic acid is the dominating species in the near-surface region, while only carbamate is formed in the bulk, to differences in solvation in the outermost IL layers as compared to the bulk situation.