Abstract
A quantitative kinetic study of the liquid phase hydrogenation of 1-butene, 1,3-butadiene and 1-butyne on rhodium supported catalysts has been performed. Unlike 1-butene hydrogenation, which can be represented by a simple Langmuir-Hinshelwood kinetic equation, the 1,3-butadiene and 1-butyne hydrogenationsfollow a more complex kinetic rate law. Comparable apparent sensitivities to metal dispersion also distinguish the 1,3-butadiene and 1-butyne, which are sensitive, from the 1-butene which is not. As previously shown with 1-butyne on platinum and palladium, the results obtained on rhodium can also be interpretated by a “multicomplexation” mechanism where the active sites, on metallic surfaces constituted by atoms of low coordination number, are reversibly deactivated by the adsorption of two molecules of 1-butyne. The feature for rhodium is that this “multicomplexation” effect is observed not only for 1-butyne but also for 1,3-butadiene. In conclusion, a single kinetic model can account for four systems: Pt-butyne Pd-butyne, Rh-butyne and Rh-butadiene. This kinetic interpretation allows us to determine a “multicomplexation” coefficient K' which depends on the metal dispersion and an intrinsic rate constant k which is independent of the metal dispersion. Finally a quantitative activity classification is obtained for the three metals and the three hydrocarbons studied.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
