Carbon supported Ru catalysts as promising alternative for Raney-type Ni in the selective hydrogenation of d-glucose

Abstract

The activity, selectivity and stability of Ru/C catalysts in d-glucose hydrogenation have been compared with those of the conventional catalysts for this process, viz. Raney-type Ni. All catalysts show high selectivity to d-sorbitol (>98%). Promoting Raney-type Ni with Mo and Cr/Fe has a positive effect on the hydrogenation rate. The Cr/Fe promoted system exhibits the highest activity but the Fe leaches from the catalyst into the reaction mixture. Moreover, this catalyst deactivates after successive runs. For all Raney-type Ni catalysts leaching of Ni in the product mixture occurs. Carbon supported ruthenium is an attractive alternative for Raney-type catalysts. The Ru/C catalysts have higher activities, while Ru does not leach. The activity is proportional to the Ru surface area, independent of the preparation method. A novel anionic deposition method renders catalysts with dispersions of 40%.