1992 Volume 78 Issue 1 Pages 42-49
As for the estimation of the rates of gas-solid reaction and gas-gas reaction with solid catalysts, an accurate measurement is very important for determining the surface area of solids. Therefore, the measuring method of metal surface area should be standardized for the comparison of actual reaction rate. However, the surface area cannot be easily evaluated from geometric shape even in the case of dense metal, because the true surface area depends on the surface roughness. In this paper, the measuring method of dense metal surface area by electrolytic solution was developed for the dense metal of irregular shape and/or non-smooth surface.
According to the TAFEL's equation, a linear relationship exists between the current, Itotal, in circuit and the solid surface area, S, of the cathode under the given conditions. This principle was adopted as the measuring method. Optical glass was selected as the standard reference material for determining the surface area. By this method, the linear relationships were measured between Itotal and S for nickel and iron.
When the surface roughness and geometric surface area assuming that the surface is smooth were known, the surface area of catalytic metals could estimate by using the present results, and then, the surface area could be directly measured by this method even the surface roughness and/or geometric surface area were not known.