Competitive hydrogenation of olefinic substrates on a Pt/SiO2 catalyst

The effect of structure of substrates and solvents on the process of competitive hydrogenation of binary mixtures of olefinic substrates in the liquid state on 5% Pt/SiO₂ catalyst has been investigated. The hydrogenations were carried out at 20°C under atmospheric pressure of hydrogen in the absence of solvent, in methanol and in cyclohexane; one series was also performed in sec-butanol and in tert-butanol. Selectivity changed markedly owing to the different adsorptivity of the substrates. In more polar solvents hydrogenation of less polar substates was relatively preferred.