Anchoring of bimetallic particles on nanostructured carbon materials to promote the formation of organometallic intermediates leading to the selective dehydrogenation of n-butane

Abstract

This study reports the development of Pt-based bimetallic catalysts on carbonaceous supports for direct non-oxidative n-butane dehydrogenation. Bimetallic particles are anchored at defects on the support surfaces. The support is crucial for establishing a proper bimetallic phase, while the promoter (Sn, In, Ga, Ge, Pb, or Zr) alters the Pt metallic phase through geometric and electronic effects, enhancing catalytic performance. The geometric effects of the bimetallic phase facilitate C-H cleavage and butane adsorption in an inclined position, as opposed to flat positioning; this specific organometallic intermediate helps prevent side reactions. Meanwhile, the electronic effects boost the electronic density at Pt sites, promoting olefin desorption and reducing coke formation. The combination of these effects proves particularly beneficial for In, Ge, and Ga in catalysts based on carbon nanotubes, as well as for In, Ge, and Sn in those supported on Vulcan carbon.