Their diagnostic character reveals imperfections of CO2 cathode layers and thereby helps improve electrolyzer designs. More broadly, the concept of the CCC diagnosis can be applied to other types of CO2 electrolyzer cells, for instance, those converting CO2 to hydrocarbons on pyrolysis (Pyrolysis/Acid-washing/ Pyrolysis/Acid-washing/ Pyrolysis/Acidwashing/Pyrolysis). +2 mA in 0.2 mA steps. XPS (X-ray photoemission spectra) was conducted on a K-Alpha Xray photoelectron spectrometer system (Thermo Scientific) with Hemispheric 180° dual-focus analyzer with 128-channel detector. X-ray monochromator was microfocused Al Kα radiation.