Bond energy, metal-oxygen

Fio. 56. The dependonco of tho bond energy of oxygen with the. surface of the oxide catalyst, Qo-. ie Om> kcal, found by the kinetic method, and the bond energy of the metal with oxygen in a solid oxide, Qo—Me > koal, estimated thermochemically from the heat of formation of this oxide from elements (390), on the atomic number n. 

Kulkova and Temkin have determined the bond energies of oxygen with various metals Qaus (377). Table XXV is based on their data, which were obtained by the method of adsorption-chemical equilibria. 

Fourth, a parallelism is observed between the bond energies of oxygen with oxide catalysts obtained by the kinetic method Qo—mc o the bond energies of oxygen with a metal in these oxides, found thermochemically Qq—Me (Fig- 56). 

Fig. 8. Energies calculated with a polarizable continuum model, differences of the sums of all metal-oxygen bond lengths, AS(M-O), and energy profiles for water exchange on rhodium(III) and ruthenium(II) hexaaqua ions.

The result is that for minimum activation energy, the bond YZ must be stretched and weakened before the final bond XY is established. Quantitative calculations show that the activation energy evaluated in this manner amounts, at the most, to 7 % of the bond energy YZ. In accordance with this theory, recombinations of atoms of hydrogen, nitrogen, oxygen, chlorine on metal surfaces... 

---