Catalytic behavior of a cation in a solid solution-An electrostatic potential approach

A method to calculate the electrostatic potential at a surface cation site and at an adsorbate site is described. The method is applied to evaluate the difference in the electrostatic potential at the two sites when the cation is placed in different oxide solid solutions of the same crystal structure. It is concluded that the ability of the cation to accept an electron from the adsorbate increases if the cation is in a more ionic oxide matrix, and vice versa. This conclusion appears to be consistent with published experimental data involving adsorption and catalysis on a number of solid solutions.