Catalytic decomposition of hydrogen peroxide by a flow-through self-regulating platinum black heater Original Research Article

A flow-through reactor where a fine platinized platinum wire (Pt black wire) runs through the entire length of the PTFE tube was fabricated for the rapid decomposition of hydrogen peroxide (H2O2) at concentrations up to 1 M. Since the Pt black wire is directly electrically heated and the exterior of the tubular reactor is well insulated, the energy efficiency of this heater reactor is excellent. The temperature coefficient of resistance of the wire is significant (3280±40 ppm/°C). This provides a means to ascertain the mean temperature by measuring the resistance of the wire. The concentration of residual H2O2 was determined by the hematin-catalyzed oxidation of nonfluorescent thiamine to fluorescent thiochrome by H2O2. Essentially, quantitative (99.997%) decomposition of 1 M H2O2 could be achieved at a mean reactor temperature of 108 °C from a neutral aqueous solution with a mean residence time of ∼270 s.