Catalytic activity of the chemically polymerized polypyrrole towards hydrogen peroxide decomposition

Catalytic activity of polypyrrole prepared by a chemical method using ferric chloride as an oxidant has been investigated in the decomposition of hydrogen peroxide. Elemental analysis and Energy Disperse Spectrum X-ray technique (EDX) were reproducible and confirmed the presence of FeCl 4 - as a counter ion. Polypyrrole was stable at [H 2 O 2 ] lower than 0.1 M. The reaction followed first-order kinetics, and both the rate constant and activation parameters were determined. Enhanced activity was observed with increasing pH. Increasing the initial [H 2 O 2 ] led to a decrease in the reaction rate, which is attributed to the stability of the polymer at lower [H 2 O 2 ]. Electrical conductivity of polypyrrole was measured before the reaction and as a function of the initial concentration of H 2 O 2 . Increasing [H 2 O 2 ] led to a decrease in the electrical conductivity from 22 S/cm before reaction to 1.48 S/cm at [H 2 O 2 ] of 0.05 M. A probable reaction mechanism has been suggested.