The catalytic reaction network for the Cu catalyst is depicted as a directed graph in Figure (CO2 hydrogenation on the Pd catalyst is discussed in Section S3). Notably, the CO2 hydrogenation network encompasses the CO hydrogenation network. The size of node marks indicates free energies at standard conditions relative to isolated CO2 gas and H2 gas (∆𝐺 ! ) and considering that each C-O cleavage leading to the formation of OH* is then followed by the removal of H2O from the surface. Edge colors represent either transition state energies relative to isolated CO2 gas and H2 gas (∆𝐺 #$% ‡ , Figure ) or absolute barriers (∆𝐺 ‡ , Figure ) calculated relative to their reference initial states. Please note that ∆𝐺 #$% ‡ and ∆𝐺 ‡ include the energy of co-adsorption of the reacting species, as detailed in Section S4. While Section S5 presents a comprehensive tabulation of thermodynamic and kinetic parameters, we outline general reactivity trends below. Thus, the final C2 oxygenate clusters can be reached on Cu via two kinetically feasible pathways.