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 500°C and 7.0 MPa, probably due to the Ru crystals covered by promoter and support materials and/or sintering of Ru crystals.