Influence of chemical exfoliation process on the activity of NiCl2-FeCl3-PdCl2-graphite intercalation compound towards methanol electrooxidation

Abstract

In the present work the influence of chemical exfoliation process of quaternary graphite intercalation compound (NiCl2-FeCl3-PdCl2-GIC) on its catalytic activity in the methanol electrooxidation reaction was examined. NiCl2-FeCl3-PdCl2-GIC was synthesized by a molten salts method using purified flaky graphite and anhydrous metal chlorides as reactants. The process of intercalation was carried out at 450°C for 72h. To obtain exfoliated graphite intercalation compound (NiCl2-FeCl3-PdCl2-EGIC), a part of gathered product underwent chemical exfoliation in hydrogen peroxide solution. Crystalline structure of the obtained GIC and product of its exfoliation was characterized by XRD while the their morphology by SEM and TEM techniques. Development of the surface area was calculated by BET method. Electrochemical activity of both materials were examined in the model process of methanol electrooxidation by cyclic (CV) and linear sweep (LSV) voltammetry as well as potentiostatic method.The XRD and SEM analysis have showed that the chemical exfoliation process contributes to the changes in structure and morphology of the examined material.From the electrochemical results it is revealed that prepared NiCl2-FeCl3-PdCl2-GIC exhibits activity towards electrochemical process of methanol oxidation. Furthermore is proved that electroactivity of the examined NiCl2-FeCl3-PdCl2-GIC significantly increases due its chemical exfoliation.