In this work, we investigate the decomposition dynamics
of formate
(HCO2), which is an important reaction intermediate in
many catalytic processes, on three model catalyst surfaces of Cu:
Cu(111), Cu(110), and Cu(100). The decomposition proceeds via the
conversion of a bidentate adsorption configuration to a less stable
monodentate configuration followed by the cleavage of the C–H
bond. Classical trajectory calculations on first-principles-based
neural network potential energy surfaces were carried out to understand
the post-transition state dynamics for HCO2 decomposition.
Our results showed that the CO2 product is translationally
hot with angular distributions sharply collimated along the surface
normal, in agreement with experimental measurements. Furthermore,
the CO2 product was found to possess vibrational excitations,
mostly in the bending modes. These product state distributions are
rationalized by the Sudden Vector Projection model, revealing the
key role of the transition state in the product energy disposal of
this surface reaction. These dynamical results are compared with available
experimental data, shedding light on the structure sensitivity in
formate decomposition dynamics.