In situ Raman spectroscopy of reactions in supercritical water

The decomposition of hydrazine (N[sub 2]H[sub 4]) in near-critical and supercritical water is studied by in situ Raman spectroscopy. A high-pressure, high-temperature optical cell equipped with diamond windows allows us to perform Raman measurements at up to 430[degree]C and 350 atm of water. Using the optical cell as a steady-state flow reactor, the decay of hydrazine and the production of ammonia are followed optically as a function of reaction time to yield an effective first-order rate constant for decomposition of 0.32 s[sup [minus]1] at 400[degree]C. 20 refs., 3 figs.