Nickel based monometallic and bimetallic catalysts for synthetic and real bio-oil steam reforming

Abstract Catalysts based on Ni supported on alumina were studied for steam reforming (SR) of a synthetic bio-oil/bio-glycerol mixture and a real bio-oil. Catalyst tests were carried out in a continuous fixed bed reactor at atmospheric pressure and steam to carbon (S/C) ratio of 5.0. In the case of experiments with the bio-oil/bio-glycerol mixture the initial temperature was 1073 K, then it was successively changed to 973 K and 1073 K again to assess catalyst deactivation. Experiments with the bio-oil sample were run at 1073 K. First, the effect of modifications to the alumina support with CeO 2 and La 2 O 3 was studied in monometallic catalysts. Ni/CeO 2 Al 2 O 3 was identified as the catalyst more resistant to deactivation, likely due to its higher oxygen mobility, and selected for further tests. Then, bimetallic catalysts were produced by impregnation of noble metals (Pd, Pt or Rh) on the Ni catalyst supported on CeO 2 Al 2 O 3 . Co-impregnation of Rh and Ni on the CeO 2 Al 2 O 3 support represented a further improvement in the catalytic activity and stability respect to the monometallic catalyst, leading to stable gas compositions close to thermodynamic equilibrium due to the favourable Rh Ni interactions. Rh Ni/CeO 2 Al 2 O 3 is therefore a promising catalyst to produce a hydrogen-rich gas from bio-oil SR.