Modified Bauxite Supported Ruthenium Catalysts for Hydrogen Evolution in the Water-Gas Shift Reaction

Hydrothermally treated bauxite with high surface area was used as a ruthenium-based catalyst support. A series of Ru/bauxite and 2.0% (mass fraction) Ru/Al2O3 catalysts were prepared by incipient-wetness impregnation. The loading content of ruthenium in the Ru/bauxite catalysts was varied from 1.0% to 4.0%. The catalysts were thoroughly characterized by X-ray fluorescence (XRF), low temperature N-2 physical adsorption, X-ray diffraction (XRD), H-2 temperature-programmed reduction (H-2-TPR), and CO temperature-programmed desorption (CO-TPD). The performances of the catalysts for the water-gas shift reaction were also investigated. The results indicated that Ru/bauxite catalysts possess an excellent ability to evolve hydrogen in the water-gas shift reaction. This was attributed to the interaction between Ru and Fe2O3 in the modified bauxite, which could decrease the reduction temperature of Fe2O3, and also improve the adsorption-desorption behavior and decrease the desorption temperature of Ru/bauxite catalysts for CO molecules, resulting in higher activity in the water-gas shift reaction.