Abstract
In the research for a quantitative correlation between catalytic activity and the property of various catalysts, the electronic configuration, at each catalytic atom in solid-state materials, is considered as an important factor. Comparing the reported experimental results of various pure metal catalysts for Ammonia Synthesis (AS) and Hydrogen Evolution Reaction 10 (HER), we find that the elements having suitable electronegativity and sufficient accessible half-filled orbitals are most positive for catalytic activity. It is, therefore, proposed that the half-filled orbitals interaction between reactant species and the catalytic active atom plays a decisive role in catalytic activity. The theoretical significance of this discrimination of the orbitals’ interaction in relation to the catalytic behaviors is discussed.