(35e) Catalytic Partial Oxidation of a Surrogate Diesel Fuel Mixture Using Pyrochlores: Effect of Reforming Metal

The formation of synthesis gas from diesel fuel for use in solid oxide fuel cells via partial oxidation is reduced by the deactivation of the reforming catalyst by polynuclear aromatics and sulfur compounds present in the fuel. Recently, it has been found that the substitution of active reforming metals into the structure of thermally stable oxides can produce a catalyst that is resistant to both sulfur poisoning and carbon formation. Of particular interest is recent work on La(2-x)SrxRhyZr(2-y)O(7- î) oxide [1, 2]. As prepared, this material showed both the pyrochlore and perovskite phases by XRD, and had superior resistance to deactivation by sulfur, aromatics, and carbon deposition compared to directly comparable formulations without Sr and/or Rh. However, the cost of Rh, and its low nominal dispersion in these recent studies (ca. 5%), suggest that other catalytically active metals should be investigated. Ni, Pt and Ru metal are less expensive than Rh, and are each well-know for their ability to convert hydrocarbon into synthesis gas. However, it is not known whether a pyrochlore substituted with either Ni, Pt or Ru will be able to retain its CPOX activity in this type of material, or how its activity and resistance to deactivation compare to that of a substituted Rh-based catalyst. Thus, the objective of the work reported here is to study the CPOX activity of directly comparable Ni, Pt, or Ru and Rh-substituted metal oxides. n-Tetradecane (TD) is used as a representative component of diesel fuel. Experiments are carried out with 50 ppmw of added sulfur (as dibenzothiophene) and 5 wt% of a representative aromatic (1-methylnaphthalene) to determine the activity/selectivity to syngas, and resistance to deactivation of these two catalysts.