Design of highly active and chemoselective bimetallic gold–platinum hydrogenation catalysts through kinetic and isotopic studies

Kinetic model for the chemoselective hydrogenation of nitroaromatic compounds on Au/TiO2 has been established by combining the Hougen–Watson formalism and isotopic studies. It has been found that, with this catalyst, the controlling step corresponds to the dissociation of H2 on gold atoms of low coordination. Taking this into account, a new bimetallic Au@Pt/TiO2 solid has been prepared that, when optimised, increases the rate of H2 dissociation while preserving high chemoselectivity. The resultant catalyst is the most effective catalyst reported, up to now, for hydrogenating nitroaromatic compounds in the presence of other sensitive functionalities.