How to estimate activation energy and pre exponential factor for a surface reaction


I have a list of reactions from various literatures for surface oxidation of carbon under fuel cell conditions and i want to identify/reduce these reactions to only those which are plausible. For that purpose i need to calculate the activation energy, pre exponential factor…

I have attached a simplified reaction scheme for my problem, and once i understand it, i will apply it to the complete reaction scheme that i have in hand.

For simplicity, the reaction steps is as follows: (s) stands for surface or solid phase
C(s) + H2O ↔ (C-OH)ads + H+ +e-

(C-OH)ads ↔ (CO)ads + H+ + e-

(C-OH)ads + H2O → C(s) + CO2(g) + 3H+ + 3e-

As far as i understood, i need to calculate the vibrational frequency and then use DFT to get the energies. I am very new on psi4 and not from molecular chemistry background and I therefore would appreciate if anyone could explain me with an example of the steps needed to be performed for my reactions on psi4.

I also saw that, the molecular geometry is usually used as input file for DFT analysis. How do i find the geometrical co-ordinates for the molecules, is there a database where i can find it? Or is there a way to find it on psi4 through optimization?

I kindly ask your support and I thank you in advance.