Preparation of COF2 using CO2 and F2 in the electrochemical cell with PbSnF4 as a solid electrolyte

Tetragonal PbSnF4 was prepared by precipitation method with Pb(NO3)2 and SnF2 aqueous solutions. The product was characterized using X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XFS), and the other chemical analyses. Tetragonal PbSnF4 exhibited the highest electric conductivity of 3.2 Sm−1 at 473 K in air as a fluoride ion conductor. We have investigated the possibility of COF2 formation using CO2 and F2 in an electrochemical cell with PbSnF4 as a solid electrolyte. At same time, we tried to produce an electric power from an electrochemical cell. This CO2/F2 electrochemical cell was constructed with a tetragonal PbSnF4 disk having Au electrodes. The electromotive force was about 0.9 V at room temperature for 0.1 MPa CO2/(0.01 MPa F2 + 0.09 MPa Ar). However, the short circuit current density was 0.24 A m−2, which was quite small. This current density was so small that no fluorocarbon compound was detected after 3 h discharge using FT-IR.

Emf with anode gas of 0.1 MPa CO2 and cathode gas of F2 and argon.Figure optionsDownload as PowerPoint slide