Relation between the catalytic activity of binary compounds of group ii metals with nonmetals and the position of the elements in mendeleev's periodic system Communication 5. Regularities in the change of properties in the series of ZnO, ZnS, ZnSe, ZnTe

Abstract

1. The existing empirical and theoretical works on the electronic theory of chemisorption and catalysis do not indicate what type of changes might occur in the catalytic properties of those semiconductors which do not possess d-electrons, if the metalloid anion is varied. 2. The catalytic activity of a binary MeX compound with respect to alcohol dehydration was found to change side by side with the change in bond polarity, which change also shows up in several electrical properties. When the atomic weight of the metalloid in a MeX compound is increased, the alcohol-dehydration activation energy decreases, the dielectric constant increases, the width of the forbidden band and the electronegativity difference decreases. The dependence is complicated by changes in E with the degree of surface covering. 3. On the basis of the literature data, we proposed that the catalytic action of ZnS, ZnSe, and ZnTe (possibly also ZnO) takes place in the range of predominantly intrinsic conduction. A final conclusion will only be reached after the measurements of electrical properties of semiconductors under catalytic conditions have been conducted. We assume that the position of extrinsic (impurity) conduction levels may also depend on the position of the elements constituting the semiconductor in the periodic table.