The reduction of metallic oxides with hydrogen at high pressures

Abstract

The equilibrium relation in the reaction between a metallic oxide and hydrogen is determined at any given temperature by the concentration of the hydrogen and that of the water vapour produced by the reduction. Thus, if in the equation MeO + H 2 ⇌ Me+H 2 O, C denotes the concentration of the hydrogen and C' that of the water vapour, we have the relation:— C/C' = K, where K is a constant at any given temperature. If C/C' can be arranged to be greater than K, the reaction expressed in the above equation proceeds from left to right. This state of affairs may be realised:— ( a ) By increasing the pressure of the hydrogen present. ( b ) By diminishing the pressure of the water vapour formed during the reaction. ( c ) If the reaction is endothermic, by raising the temperature, when the value of K is diminished according to van't Hoff's equation, dln K/ d T = -Q (T) /RT 2 , when ln K = Q (T) /RT+const.