flow conditions. In contrast, the PBT-2 catalyst showed excellent long-term stability
over 43 h at a WHSV of 700 h
À1 . Analysis of the reaction rate at different
temperatures (50–80
C) under continuous-flow conditions provided the basis for
Arrhenius analysis of PBT-2-catalyzed oxidation of benzyl alcohol, which revealed
that the reaction exhibits an activation energy of 79 kJ/mol and pre-exponential
factor of 1.1 Â 10
12 s
À1 (Fig. 22). These values correspond to a TOF of 1,600 h
À1 at
a reaction temperature of 60
C.
Fig. 21 Comparison of PBT-1 and PBT-2 under continuous-flow aerobic oxidation system
Fig. 22 Arrhenius analysis of continuous-flow aerobic oxidation
236
H. Miyamura and S. Kobayashi