3040.     SCHEEPERS, L.  [Catalytic Dissociation of Carbon Monoxide.]  Rev. univ. mines, vol. 19, 1943, pp. 121-131; Chem. Zentralb., 1943, II, pp. 1782-1783; Chem. Abs., vol. 38, 1944, p. 5720.

        Experiments on the dissociation of CO with catalysts of the Fe group, according to 2 CO=CO₂+C+36.4 kcal., are described in which the dissociation of CO was investigated with natural magnetite and, at the same time, the reduction of the Fe₃O₄ contained therein in a semiautomatic apparatus under a current of gas.  The crushed magnetite was separated into 3 fractions of which the 1^st (largest) was strongly magnetic, the 2d (smaller) weakly magnetic, and the 3d (about 3%) nonmagnetic with no dissociating action.  The strongly magnetic material had, in a constant gas current, at first a small and then increasing reaction; the formation of CO₂ tended to assume a constant value, even though the reduction was not yet complete.  With increasing temperature the dissociation increased up to a maximum at 550° and then decreased again.  The less magnetic material had a much stronger and almost immediate action.  Although the 1^st fraction gave, at 515°, at the start, only 2 cc. CO₂ per hr., an addition of 0.2 gm. of the 2d fraction increased CO₂ formation suddenly to 760 cc. per hr.  Natural magnetite, crushed but not separated magnetically, showed an increase of CO₂ formation with decreasing flow velocity of the gas and with decreasing grain size.  The catalytic effect of a mixture of Fe₂O₃-Al₂O₃ was investigated also with regard to the effect of CO, in which it seems that the Fe produced by the reduction leads to the dissociation of the CO.  Two types of such mixed catalyst are prepared (A) by precipitating the Fe hydroxide from a suspension of Al and calcining of the product at 750° and (5) by simultaneous precipitation of both substances and calcining as before.  Results show at first a period of rapid CO₂ formation, which gradually slows down and becomes stationary.  The catalyst mixture with 15% Al had an effect superior to all others and to Fe₂O₃.  The destruction of ceramic materials lining of blast furnaces) by CO is probably due to C precipitations in the vicinity of Fe-containing impurities, whereby even minute amounts of C are enough to disintegrate the brick.