Formation of metallic hydrides and nitrides and their significance in the synthesis of ammonia

Adsorption of nitrogen and hydrogen on lithium was investigated and the activation energy for nitrogen found to be 47 kg.‐cal./g.‐mol. The addition of other metals promoted adsorption, cerium being found the most effective. The rates of formation of calcium hydride and calcium nitride from the gases and the metal were found at first to increase with temperature up to a maximum and thereafter to decrease. The effect of high pressure on the rates of formation of hydrides and nitrides was also investigated. The possibility of synthesizing ammonia by passing nitrogen and hydrogen, alternately or in admixture, over these metals is discussed.