1. Transport Matters: Boosting CO2 Electroreduction in Mixtures of [BMIm][BF4 ]/Water by Enhanced Diffusion
- Author
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Alexander V. Rudnev, Soma Vesztergom, Yongchun Fu, Florian Stricker, Ilche Gjuroski, Peter Broekmann, Julien Furrer, and Noémi Kovács
- Subjects
Aqueous solution ,Tetrafluoroborate ,Chemistry ,Diffusion ,Inorganic chemistry ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,6. Clean water ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Viscosity ,chemistry.chemical_compound ,13. Climate action ,Ionic liquid ,Physical and Theoretical Chemistry ,0210 nano-technology ,Electrochemical reduction of carbon dioxide - Abstract
Room-temperature ionic liquids (RTILs) are promising new electrolytes for efficient carbon dioxide reduction. However, due to their high viscosity, the mass transport of CO2 in RTILs is typically slow, at least one order of magnitude slower than in aqueous systems. One possibility to improve mass transport in RTILs is to decrease their viscosity through dilution with water. Herein, defined amounts of water are added to 1-butyl-3methylimidazolium tetrafluoroborate ([BMIm][BF4 ]), which is a hydrophilic RTIL. Electrochemical measurements on quiescent and hydrodynamic systems both indicate enhanced CO2 electroreduction. This enhancement has its origin in thermodynamic/kinetic effects (the addition of water increases the availability of H+ , which is a reaction partner of CO2 electroreduction) and in an increased rate of transport due to lower viscosity. Electrochemically determined diffusion coefficients for CO2 in [BMIm][BF4 ]/water systems agree well with values determined by NMR spectroscopy.
- Published
- 2017
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