Graphitic nanofilaments as novel support of Ru-Ba catalysts for ammonia synthesis

A novel graphitic-nanofilament-(GNF-) supported Ru-Ba catalyst is prepared and used in ammonia synthesis reaction. The Ru-Ba/GNFs catalyst shows remarkably high activity and stability for ammonia synthesis, which can be attributed to high purity and graphitization of GNFs with unique structure. TEM micrographs of the Ru-Ba/GNFs catalysts show that Ru metal particles uniformly disperse on the outer wall of GNFs, and the particles become bigger than that before ammonia synthesis reaction after 50 h of operation at 500degreesC and 7.0 MPa, probably due to the Ru crystals covered by promoter and support materials and/or sintering of Ru crystals. (C) 2002 Elsevier Science (USA).