Discipline: Chemistry & Chemical Sciences
Subcategory: STEM Research
Zhe Wang - Xavier University of Louisiana
Co-Author(s): Kevin Riley, Xavier University of Louisiana
Accomplishing highly selective and efficient electrochemical CO2 reduction is essential for a sustainable utilization of fossil energy resources. Here, we report ultra-fast CO2 reduction in ionic liquids (ILs) performed in aerobic environments. CO2 reduction to CO is observed at a very low over-potentials, namely, >90% faradic efficiency and near 100% carbon selectivity. In the present article, we show that this general approach can be conducted on three conventional electrodes (Pt, Au and carbon). The reduction process is initiated by an electrochemical generation of superoxide radicals (O2.-) and followed by an efficient CO2 activation through N-heterocyclic carbene (NHC) CO2 adducts in 1-Butyl-3-methylimidazolium bis(trifluoro-methylsulfonyl) imide (BmimNTf2) IL. The observed experimental results, supported by a first principle computational modeling suggest an ECE mechanism, where O2.- superoxide efficiently transforms Bmim cations into NHC structures, and activates CO2 into NHC-CO2. This work offers a green approach for CO2 reduction under simple conditions, with potential applications in a broad range of platforms, catalytic systems, and biological processes involving O2.
Funder Acknowledgement(s): NSF HRD-1700429; NSF CHE-1832167
Faculty Advisor: None Listed,