Aromatic Ester‐Functionalized Ionic Liquid for Highly Efficient CO2 Electrochemical Reduction to Oxalic Acid

• DOI: 10.1002/cssc.202001194
• Publication Date: 2020-07-15T17:48:28Z
• Authors: Yingliang Yang; Hongshuai Gao; Jiaqi Feng; Shaojuan Zeng; Lei Liu; Licheng Liu; Baozeng Ren; Tao Li; Suojiang Zhang; Xiangping Zhang
• Keywords: Oxalic Acid

Electrochemical reduction of CO2 into valuable chemicals is a significant route to utilize resources. Among various electroreduction products, oxalic acid (H2 C2 O4 ) an important chemical for pharmaceuticals, rare earth extraction, and metal processing. Here, aprotic aromatic ester-functionalized ionic liquid (IL), 4-(methoxycarbonyl) phenol tetraethylammonium ([TEA][4-MF-PhO]), was designed as electrolyte acid. It exhibited large partial current density 9.03 mA cm-2 with faradaic efficiency (FE) 86 % at -2.6 V (vs. Ag/Ag+ ), the formation rate high 168.4 μmol h-1 , which highest reported value date. Moreover, results functional theory calculations demonstrated that efficiently activated -COOH intermediate by bis-active sites ester anion via [4-MF-PhO-COOH]- adduct, finally dimerized