Pyrolysis and Combustion of Metal Hydridesmdash;Analysis by Kinetic Spectroscopy

摘要

The flashhyphen;pyrolytic decomposition of AlH3and BeH2has been studied by kinetic spectroscopy at 2477deg; plusmn; 20deg;K. The major dissociation product seen in the flash pyrolysis of AlH3is AlH. The existence of a subhydride AlH2is postulated, and its role in the pyrolytic decomposition of AlH3is correlated to the observed species AlH. The first product seen in the flash pyrolysis of BeH2is BeH. Within a few microseconds of the appearance, the BeH is seen to decrease in intensity. At 25mgr;sec after the photoflash the first bands of BeHplus;are seen. From 60mgr;sec on, the BeHplus;is the major berylliumhyphen;containing pyrolysis product. The pyrolytic decomposition of BeH2has been observed for 165mgr;sec after the initial photoflash. The flashhyphen;induced combustion of BeH2in oxygen has been studied at 20 mm pressure of the gas. The absorption spectra of OH, BeH, BeHplus;, and BeO are described, and the relative concentration of each is given for the period of 140mgr;sec following the initial photoflash. A mechanism for the combustion of BeH2is given in terms of the spectra observed.