Dear Chiranjeevi,

I think you are asking about energy band gap not bond energy. Am a right? If it is band  energy: i) If the band gap energy is 2.0 to 2.9 eV they work well with solar light. 

             ii) above 3.0 eV the catalysts work in UV light. 

   This is with respect to semiconductor photocatalysts. I hope the answer is useful. 

The energy required to form and break the bond between the catalyst and the molecule.

Do you mean desorption from the active site?

Yes