Rotating disc method to study the dissolution kinetics of copper metal in citric acid and hydrogen peroxide

This study reports the kinetics of copper metal dissolution in citric acid-hydrogen peroxide solution using the rotating disc method. The effect of the concentration of citric acid as well as hydrogen peroxide, stirring speed, disc surface area, and temperature was investigated. The concentration of hydrogen peroxide (0.25-1.5 mol/L) has a strong effect on the dissolution rate (mg/min) of copper with a reaction order of 0.92, compared to a reaction order of 0.42 with respect to the concentration of citric acid (0.125-1.5 mol/L). The reaction rate is directly proportional to the disc area (A) and square root of the disc rotation speed (omega(1/2)), as expected from the Levich equation. The activation energy of 33 kJ/mol, in the temperature range 30-60 C-degrees is also comparable with the values reported in previous studies.