LMs were obtained by optimising the atomic positions in the reactant molecules, and the paths connecting them were determined by optimising the force-induced paths through a chain-of-state method called locally updated planes (LUPs) . During SC-AFIR exploration, an artificial force was systematically applied to atoms in the three reactant molecules and nine surface atoms highlighted in blue in the insets of Fig. , where the model collision energy parameter γ of SC-AFIR was set as 300 kJ/mol. The kinetic navigation option was used during the search to distinguish between kinetically accessible and inaccessible paths. The search was performed for a reaction time of 3,600 s at reaction temperatures of 500, 750, and 1,000 K. Gibbs energy (thermal) corrections at the LMs and the highest node along the LUP paths (PT: path top) at these temperatures were obtained by harmonic oscillator approximation of atoms in the reactant molecules. CO2 yields were counterintuitive, an additional 1000 reactive paths were sampled by the onthe-fly kinetic simulation, providing equal (0.5:0.5) initial populations to CO + O+ 2H2O and CO2 + 2H2O for the (111) case and CO + 2OH + H2O and CO2 + 2H2O for the (100) case, to find more paths for their equilibration; this did not change the trend that CO2 is not an exclusive product within the present model (see Table ), which does not account for its release into the vacuum.