Unusual inhibition effects in the F2 evolution reaction at carbon anodes

摘要: Abstract Inhibition effects in anodic F2 evolution reaction at carbon electrodes KF·2 HF melt are described and characterized by means of cyclic-voltammetry experiments, galvanostatic steady-state current-potential relations “iR-drop” measurements. With potential cycling, or after successive polarization runs, an anodically formed fluorinated-C film develops on the anode surface strongly inhibits current. Once steady reproducible conditions reached, such a exhibits non-ohmic, barrier-layer behaviour high current densities, while only small normal ohmic impedance arises lower currents. For latter conditions, intrinsically Tafel slope ca. 0.45 V which is probably not due to effects. A change state occurs above 4.5 vs. PdH.