This project involves kinetic studies of both organic and inorganic species in the hydrothermal environment.  Rates of decomposition, as well as decomposition mechanisms can be elucidated given the appropriate instrumentation.
 

Phase diagram of water.  The region of study (i.e hydrothermal environment) is indicated.
 

Hydrothermal environment:  T = 150 °C - 320 °C   P = 275 bar
The Critical Point of Water:  T = 374 °C  P = 221 bar

A variety of environmental issues stimulate our interests and work in hydrothermolysis chemistry.  One application is the small molecule chemistry that occurs in geothermal "black smoker" vents in the deep-ocean rift zones.   The kinetics and mechanisms of these reactions are thought to have contributed significantly to the origin of life.  Our hydrothermolysis reaction studies also apply to the field of hazardous waste destruction.  A potential technology there involves the use of reactions in supercritical water. For both of these applications we are studying the kinetics and mechanisms of reactions in fluid water above 200°C and 275 atm.  FT-IR and Raman spectroscopy are employed for real-time studies.  This hostile environment calls for considerable effort in the IR cell design and data analysis.   A flow reactor with diamond or sapphire windows and steel (316 SS), Ti, or Pt/Ir walls is used.  The results are useful for modeling processes to destroy hazardous waste as well as how small molecules react to form building-block molecules for simple living systems.

*1Tunnicliffe V. American Scientist, 80, p. 336-349
 
 

All the cells described below are custom designed and are not commercially available.

316 Stainless Steel Cell:
Used with sapphire or cubic zirconia windows.  The cell maintains its seal up to 330° C at 275 bar.

Titanium Cell:
This cell is more resistant to acid than the steel cell. It is used with sapphire  windows. It seals more readily than the steel cell and the seals have been maintained up to 340° C.

*316 stainless steel and titanium cell

Platinum-Iridium Cell:
This cell  was used in conjunction with diamond windows. This cell has the disadvantage of being very expensive, but the  advantage that the IR spectral window of diamond is much wider than sapphire. This means that more chemical species can be detected.

*Platinum-iridium