Über physikalische Vergiftung und Adsorptionseigenschaften von Feststoffkatalysatoren

Abstract

The hydrogenation reaction of benzene to cyclohexane at temperatures of 100 to 200 °C on two nickel-catalysts was studied experimentally. It was shown that due to physical adsorption of inert vapours such as n-hexane, iso-octane, decaline or the reaction product cyclohexane, a physical poisoning of the catalysts takes place.
Taking the adsorption equilibria in mixed vapour phases into account, the relative catalytic activity F was found to be some function of the coverage θ_G of the catalyst surface with poison. For a microporous catalyst an equation F = 1/(1+ 0g) could be established. The poisoning of a macroporous catalyst followed the equation F = 1/(1 + θ_G). It was further found, that in the case of benzene hydrogenation departures from the Arrhenius law are due to such poisoning phenomena.