Five Ba-promoted Co-Ce catalysts for NH3 synthesis were prepd. by alk. copptn. from aq. soln. of Co and Ce nitrates and impregnation with Ba(NO2)(2). The catalysts were then tested by physisorption of N-2, thermogravimetric anal. and temp.-programmed desorption of H-2 as well as for catalytic activity in NH3 synthesis under pressure 6.3 MPa. Activity of the catalysts was higher than that of a corn. fused Fe catalyst. The most effective precipitant was K2CO3,