Shape and Transition State Selective Hydrogenations Using Egg-Shell Pt-MIL-101(Cr) Catalyst

Abstract

The use of the metal organic framework MIL-101(Cr) as support for Pt nanoparticles is evaluated in three selective hydrogenation reactions. Homogenous Pt nanoparticles of ∼4 nm can be formed inside the porosity of MIL-101(Cr) in close contact with the Cr trimers in an egg-shell configuration by a wet impregnation procedure combined with sonication. The catalyst is applied in the selective hydrogenations of olefin mixtures, benzonitrile, and linoleic acid. In the case of an olefin mixture, 1-octene is selectively hydrogenated over 1-hexadecene, attributed to diffusion limitations that favor the hydrogenation of the smaller substrate. In the case of benzonitrile hydrogenation, benzylamine is selectively formed over dibenzylamine attributed to transition state selectivity. In the hydrogenation of linoleic acid, selectivities were similar to that for platinum on alumina.