Effect of the structure of the ortho, meta, and para isomers of perhydroterphenyl on their reactivity in heterogeneous catalytic dehydrogenation

The kinetics of the dehydrogenation of the individual ortho , meta , and para isomers of perhydroterphenyl and their mixtures over a (3 wt % Pt)/C catalyst has been investigated in a flow reactor at 280–340°C. The rate of the isomerization of the stereoisomers of the initial substrate (perhydroterphenyl) and terphenyl dehydrogenation products has an effect on the hydrogen release kinetics. The highest reactivity in isomerization is shown by the ortho isomer. The largest amount of hydrogen (7.0 wt %) is released in the dehy-drogenation of perhydro- meta -terphenyl and perhydro- para -terphenyl, whose conversion at 320°C is 96%.