Effect of anion in diluted imidazolium-based ionic liquid/buffer electrolytes for CO2 electroreduction on copper
Effect of anion in diluted imidazolium-based ionic liquid/buffer electrolytes for CO2 electroreduction on copper
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DOI：
10.1016/j.electacta.2020.136787
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发表时间：
2020-11-20
影响因子：
6.6
通讯作者：
Biddinger, Elizabeth J.
中科院分区：
文献类型：
--
作者：
Golru, Samaneh Sharifi;Biddinger, Elizabeth J.
一系列含有相同阳离子的离子液体（1-丁基-3-甲基咪唑鎓（[BMIM]（+）），但阴离子不同（双（三氟甲基磺酰基）酰亚胺（[NTF 2]（-））、三氟甲磺酸酯（[OTF]（-））、乙酸酯（[Ac]（-））、氯化物（[Cl]（-）），和双氰胺（[DCA]（-）研究了阴离子在稀咪唑基离子液体中的作用。缓冲电解质对CO2电还原铜电极的产物选择性和活性的影响。在CO2饱和的电解质中加入离子液体，起始电位向更正的电位移动。在所有电位下，与没有任何IL的电解质相比，所有IL（除了[BMIM][DCAD）的甲酸盐的法拉第效率（FE%）增加。在-0.92V下观察到[BMIM][NTF 2]的最大FE甲酸盐（38.7%）。[BMIM][DCA]对氢的FE%最高，对烃的FE%最低。通过使用X-射线光电子能谱，获得最大量的IL吸附在表面上的[BMIM][DCA]具有最高的亲水性和最低的CO2亲和力。这些结果强调了使用离子液体进行CO2电还原时阴离子的重要性。(C)2020爱思唯尔有限公司保留所有权利。
A series of ILs containing the same cation (1-butyl-3-methylimidazolium ([BMIM](+)) but different anions (bis(trifluoromethylsulfonyl)imide ([NTF2](-)), triflate ([OTF](-)), acetate ([Ac](-)), chloride ([Cl](-)), and dicyanamide ([DCA](-))) were used to study the effect of anion in diluted imidazolium-based ionic liquid/buffer electrolytes on product selectivity and activity of copper electrodes in CO2 electroreduction. The onset potential shifted to more positive potentials by adding ILs to the CO2-saturated electrolytes. Faradaic efficiency (FE%) of formate for all ILs (except for [BMIM][DCAD increased compared to the electrolyte without any IL at all potentials. The maximum FEformate (38.7%) was observed for [BMIM][NTF2] at -0.92V. [BMIM][DCA] had the highest FE% for hydrogen and the lowest FE% for hydrocarbons. By using X-ray photoelectron spectroscopy, the maximum amount of IL adsorbed on the surface was obtained for [BMIM][DCA] which had the highest hydrophilicity and lowest CO2 affinity. These results underscore the importance of anions when using ILs for CO2 electroreduction. (C) 2020 Elsevier Ltd. All rights reserved.