In-situ XRD studies during electrochemical processes in the ternary CrO3H2SO4-graphite intercalation compound Original Research Article

The results of this paper have shown that the ternary stage-2 CrO3H2SO4-graphite intercalation compound is electrochemically formed on the subsequent intercalation of H2SO4 into the host stage-5 CrO3-GIC/graphite matrix. In contrast to the binary H2SO4-GIC easily deintercalated upon cathodic reduction, stage-(4–6) CrO3H2SO4-GICs are preserved despite the application of a deintercalation potential as low as −0.2 V vs the Hg/Hg2SO4/18M H2SO4 as the reference. An increase in the overpotential of the reaction of hydrogen evolution is noted during deintercalation of the ternary compound. The product of deintercalation of stage-2 CrO3H2SO4-GIC with water appeared to be of the same stage number as the starting CrO3-GIC but of a better ordered structure.