Carbon-supported cobalt catalysts promoted with barium and cerium were synthesized, characterized and tested in NH3 synthesis. Two different methods of addition of the cerium promoter were used, i.e., subsequent impregnation and co-impregnation. The method of addition of the cerium promoter proved to be a crucial factor in the preparation of efficient Co-Ce-Ba/C catalysts. The co-impregnation method is more beneficial and leads to obtaining a well-dispersed catalytic material with the highest activity. The carbon-supported cobalt catalyst promoted with barium and cerium is more active than the magnetite-based commercial catalyst, especially at high conversion degrees, which means that it is less inhibited by ammonia. (c) 2013 Elsevier Inc. All rights reserved.