353.     BRILL, ------.  [BRIDGMAN, P. W.]  Behavior of Calcium in the Ammonia Catalyst Toward Poisoning.  FIAT Reel R-19, frames 7088-7104, 1941.

      Test results on Fe catalysts containing Ca for the NH₃ synthesis proved that an addition of Ca in combination with the usual addition of Al has several advantages.  Above all, the resistance of the catalyst to poisoning by CH₄ and H₂S is increased.  Tabular data present further details.  A number of catalysts with and without Ca are arranged according to the degree of their sensitivity to H₂S, H₃P, CH₄, and O₂.