Figure 3.

Proposed reduction mechanism of (a) CO₂ hydrogenation to COOH on TiC(001), (b) CO₂ dissociation to CO + O on ZrC(011), and (c) CO₂ hydrogenation to HCOO on TiC(111). From left to right: initial state, in which the reactants are adsorbed on the surface of the catalyst; transition state, identified through the presence of one imaginary frequency related to the formation of the desired product; and final state, in which the product is adsorbed on the surface of the reactant. The color scheme is as follows: Ti, blue; Zr, green; C, brown; O, red; and H, pink.