Efficient and Continuous Decomposition of Hydrogen Peroxide Using a Silica Capillary Coated with a Thin Palladium or Platinum Layer

The decomposition of hydrogen peroxide (H2O2) was studied using a silica capillary tube (o.d. 0.45 mm, i.d. 0.33 mm, length 1000 mm) coated with a thin palladium (Pd) or platinum (Pt) layer. The inner walls of the capillary were coated with a homogenous thin layer of metal by electroless plating. This metal-coated capillary provided rapid and continuous decomposition of H2O2 at room temperature within a residence time of 9.6 s, simply by passing the solution through the capillary. A capillary without Pd or Pt coating was unable to decompose H2O2 even at 50 degrees C. Pt proved to be a better catalyst than Pd. We also studied the effect of temperature, pH, concentration of H2O2 and the residence time on decomposition of H2O2.