REACTION OF FUSED SILICA WITH HYDROGEN GAS

Fused silica and flowing hydrogen gas react in the experimental temperature range of 1200° to 1400°C to form SiO and H2O vapors. Above a critical flow rate of hydrogen gas, the reaction rate is independent of gas flow rate and is not transport-controlled. The apparent activation energy for the overall process was 343±33 kj /mol (82±8 kcal/mol). The rate-limiting step is deduced to be desorption of the product from the glass surface.