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

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 (H(2)O(2)) 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/degreesC). This provides a means to ascertain the mean temperature by measuring the resistance of the wire. The concentration of residual H(2)O(2) was determined by the hematin-catalyzed oxidation of nonfluorescent thiamine to fluorescent thiochrome by H(2)O(2). Essentially, quantitative (99.997%) decomposition of 1 M H(2)O(2) could be achieved at a mean reactor temperature of 108 degreesC from a neutral aqueous solution with a mean residence time of similar to270 s. (C) 2004 Elsevier B.V. All rights reserved.