Studies on catalysis by molten metal. V. Kinetics of the dehydrogenation of sec-butyl alcohol over the liquid indium catalyst

The dehydrogenation of sec-butyl alcohol was studied by using a device of rectangular duct type reactor containing liquid indium catalyst. The experimental conditions were as follows: temperature 450-550 °C, total pressure 1 atm, partial pressure of alcohol 0.1-0.4 atm, feed rate of alcohol 0.0937-0.6 mole/hr. The experimental results were found to obey a Langmuir-type rate equation, W = k₁⁰_ρ{variant}A (1 + K_AP_A), which indicates that the surface unimolecular decomposition will be the rate controlling step. The respective values of K_A and k₁⁰ were 1 × 10^-3 exp (13,000/RT) atm^-1 and 3 × 10⁶ exp (-28,000/RT) cm/sec. The comparison of the experimental value of K_A with the value estimated by statistical thermodynamics suggested that the adsorbed alcohol may be mobile on the surface of liquid indium. Further, the assumption of a mobile activated complex gave a theoretical k₁⁰ value which agrees fairly well with the experimentally determined value of k₁⁰.