Anodic oxidation of CrO3-graphite intercalation compounds in sulfuric acid

Anodic intercalation-deintercalation of 18 M sulfuric acid into chromium trioxide-graphite intercalation compounds (CrO3-GICs) is examined in comparison with the process occurring for pure graphite. Distinct differences in the influence of the CrO3 dissolved in acid and intercalated into graphite on the intercalation process of H2SO4 are demonstrated by means of galvanostatic and cyclic potentiodynamic methods. The proposed model of intercalation of H2SO4 into CrO3-GICs concerns both electrochemical process and chemical reactions involving the CrO3 intercalant. To account for surprising effects found in the curves recorded for CrO3-GICs the changes proceeding from the structural and chemical properties of these compounds because of intercalation of sulfuric acid are considered.