2296.     MITTASCH, A., AND KUSS, E.  [Ammonia Synthesis With Catalysts Derived From Complex Cyanides of Iron.]  Ztschr. Elektrochem., vol. 34, 1928, pp. 159-170; Chem. Abs., vol. 22, 1928, p. 2441.

        Complex cyanides of Fe or carbides derived from these cyanides are not themselves effective catalysts fort he synthesis of NH₃.  The active agent is elementary Fe resulting from the decomposition and reduction of the complex cyanide.  The activity of the Fe may be enhanced by the presence of other materials that arise during the decomposition of the complex cyanides.  The effective catalyst is then only a promoted Fe catalyst.  This conclusion is supported by extensive chemical, X-ray, and magnetic studies of the complex cyanides and their decomposition products.  The bearing of this research on the NH₃ catalyst patent situation in Germany is indicated.