Photometric determination of the rate of H2O formation from H and OH in the presence of phosphine combustion products

✍ Scribed by Allen Twarowski

• Book ID: 103038380
• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 614 KB
• Volume: 94
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(93)90118-m

✦ Synopsis

Laser photolysis experiments are reported in which gas-phase H20 at 1960 K is photolyzed to H and OH radicals and the rate of recombination is measured. Previously, the rate of net H + OH recombination was determined by photometric measurements of OH radicals. In this article, photometric measurements :at 192 rim, where H20 absorbs at elevated temperatures, are reported. When small quantities of PH 3 combustion products are present in the test gas mixture, the rate of relaxation of the system to its initial state is increased substantially. A reaction model previously used to analyze OH kinetic data satisfactorily describes the time evolution of the H20 signal. These results confirm the hypothesis that phosphine combustion products open new channels for recombination of H and OH that compete with the three-body recombination reaction, H + OH + M ~ H20 + M.