Another very interesting and singular role of uranium and its compounds is that of catalysts for many chemical reactions. 

   Ammonia synthesis from nitrogen and hydrogen is sometimes accomplished in the presence of uranium carbide. Uranium oxide accelerates the oxidation of methane by oxygen, the production of methyl and ethyl alcohols from carbon monoxide and hydrogen, and the preparation of acetic acid. Not a few products of organic chemistry are obtained with the aid of uranium catalysts.

   The chemistry of uranium is very lavish. It may be hexa-, penta-, tetra-, or trivalent in its compounds. Uranium compounds of different valence differ so greatly that its chemistry is like a combined chemistry of four different elements.

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