12.     AKAMATSU, H., AND SATO, K. [Catalytic Decomposition of Carbon Monoxide by Iron.] Bull. Chem. Soc. Japan, vol. 22, 1949, pp. 127-131; Chem. Abs., vol. 44, 1950, p. 7637.

    Pure CO was passed through a quartz reaction tube containing a piece of Kahlbaum's electrolytic Fe as catalyst. Gas flowing from the reaction tube passed through Ba (OH)₂ solution, which becomes turbid when the reaction proceeds as 2 CO Π C + CO₂. 5-10 hr. are necessary for decomposition to begin at 500° reaction temperature and CO flow of 400 cc. per hr. Once started, the reaction proceeds smoothly, and free C forms on the surface of the catalyst. Electron-diffraction patterns of the catalyst were taken just as decomposition had begun, as shown by turbidity of the Ba (OH)₂ solution, and after 15 hr. of decomposition. In case 1 no free C was found, but the Fe had lost its metallic luster, the pattern obtained was that of cementite. The 2d pattern was made when the surface was black or gray in parts but before C appeared in powder form; this pattern was principally of C, but some cementite spacings also appeared. Prolonged decomposition yielded a C-powder layer and the surface then gave only C spacings. Patterns of amorphus C ordinarily show only spacings corresponding to '(hk0) and (001), but since the C resulting from decomposition of the CO showed spacings corresponding to (101) and probably (112) this deposit proved to be graphite. Since amorphus C must be heated above 2,500° to be graphitized, it is thought that in this case the C formed is not amorphus, but rather graphite formed by decomposition of cementite. Traces of 0₂ in the CO prevented decomposition if an Fe plate was used as catalyst, but not if pulverized Fe was used.