Applied Catalysis A: General, Vol.456, 223-232, 2013
Study of the synergistic interaction between nickel, gold and molybdenum in novel modified NiO/GDC cermets, possible anode materials for CH4 fueled SOFCs
The present study concerns the structural and physicochemical characterization of novel Au-Mo-NiO/GDC cermets, alongside with measurements of their carbon tolerance. This is an investigation on whether commercially available NiO/GDC powder that is modified with Au and/or Mo can yield possible electrocatalysts as anodes for CH4 fueled SOFCs. Specifically, the performed preparation methods of deposition-precipitation and deposition-coprecipitation permitted the modification of a commercial electrocatalyst and lead to cermets that exhibit different reaction kinetics for the catalytic dissociation of CH4 and different performance for CH4 steam reforming. The most interesting structural findings were observed in the reduced form of the prepared powders, where a bimetallic Ni-Au solid solution is formed in the Au-modified sample. In the ternary composite material a trimetallic Ni-Au-Mo solid solution is formed, which induces a controversial synergistic effect on the sample's catalytic performance. On the other hand, the presence of Au compared to Mo shows the best combination of results in terms of structural properties, carbon tolerance and selectivity to the desirable products of H-2 and CO, for the reaction of CH4 steam reforming. (C) 2013 Elsevier B.V. All rights reserved.
Keywords:Ni/GDC;Gold and/or Molybdenum doping;Synergy;CH4 dissociation;CH4 Steam reforming;Carbon deposition