Fig. 1. Energy (eV) as a function of integrated path length (Å) for ethane dehydrogenation (top) and ethyl dehydrogenation (bottom) on Pt 1 1 0 (1 × 2). ‘phys’ stands for physisorbed.

Fig. 2. Snapshots of the pathways for TS1, TS2, TS3 and TS4 (top to bottom). The left and right panels correspond to local minima and the middle panel to the transition state in each case. The other two panels are snapshots of an intermediate geometry along the corresponding path. The vertical displacement of each panel is intended to indicate the relative energy of the corresponding structure. A cutoff of 2.1 Å was used in drawing the bonds to Pt.

Fig. 3. Geometrical details of the transition state and chemisorbed minimum for TS1 (top left pair), TS2 (top right pair) and the two chemisorbed minima with the intervening transition state for TS3 and TS4; the distances are in Å.

Properties of the stationary points involved in ethane dehydrogenation

Energies are in eV. The energy of the lowest minimum for the paths corresponding to TS1 and TS3 was chosen as the arbitrary zero for C₂H₆ and C₂H₅, respectively. E₁ and E₂ are the energies of the higher and lower minimum for each path, E_TS is the energy of the TS, and ΔE₁ and ΔE₂ are the corresponding barriers. The final column gives the unique negative Hessian eigenvalue at the transition state in eV Å⁻².