Adsorption and hydrogenation of CO on ultradisperse iron powders
Catalytic activity in the reaction CO + H2 and adsorptivity toward CO and H2 were studied for ultradisperse iron powders prepared by the decomposition of Fe(CO)5 in a hydrogen plasma (I) and by the vaporization-condensation method (II). The specific catalytic activity of samples II was three to live times higher than that of samples I; the selectivity of the formation of C2-C3 olefins was 37-40% for I and 27-30% for II, and the olefin/paraffin ratios were 4-5 and 1, respectively. CO adsorption isotherms and isosteres measured for two types of ultradisperse iron powder in the temperature range 298-538 K are indicative of the presence of two types of adsorption sites. The catalytic reaction on powders I promoted adsorption of CO and changed its character.