Specifics of the stearic acid deoxygenation reaction on a copper catalyst

Decarbonylation of stearic acid, which is industrially manufactured from oils and fats, to higher olefins on a Cu/gamma-Al2O3 catalyst has been first studied. It has been shown that the selectivity for heptadecenes is 67% and that for CO is close to 100% at 350A degrees C. The activity of this catalyst in the further hydrogenation of resulting heptadecenes to heptadecane is well below that of a palladium catalyst. The conversion is slightly varied when hydrogen pressure increases from 4 to 14 bar; however, the selectivity for olefins increases and the selectivity for paraffins remains low. According to quantum-chemical simulation data, hydrides form on the surface of copper clusters in the presence of hydrogen. It is presumably these compounds that inhibit the side oligomerization reaction of olefins. The hydrogen-to-water concentration ratio does not affect the selectivity for CO and CO2; the only effect of the presence of water is a decrease in the stearic acid conversion rate.