CO₂ Hydrogenation to Formic Acid on Ni(111)

Abstract

Periodic, self-consistent, density functional theory (DFT) calculations are employed to study CO 2 hydrogenation on Ni(111). CO 2 hydrogenation with H adsorbed on the surface and with H absorbed in the subsurface is investigated systematically and the respective microscopic reaction mechanisms are elucidated. We show that on Ni(111), CO 2 hydrogenation to formate intermediate is more favorable than to carboxyl intermediate. The hydrogenation to formate goes through the unidentate structure that rapidly transforms into the bidentate structure. Further hydrogenation from formate to formic acid is energetically more difficult than formate formation. Formation of adsorbed formic acid from adsorbed CO 2 and surface hydrogen is an endothermic reaction. Because subsurface H in Ni(111) is substantially less stable compared to surface H, its reaction with adsorbed CO 2 to adsorbed formic acid is an exothermic one. Our results may have significant implications for the synthesis of liquid fuels from CO 2 and for catalytic hydrogenation reactions in general.2

Boron Nitride‐supported Sub‐nanometer Pd6 Clusters for Formic Acid Decomposition: A DFT Study

“…The bent CO 2 geometry is also the preferred one on a reduced ceria support . The stability of this structure with respect to the classical linear CO 2 geometry in fact depends on the metal: as examples on Ru(0001) the bent structure is more stable than the linear one, whereas on Pd(111) and Ni(111) physisorbed linear CO 2 is favored . On Pd 6 , we find that the bent structure is 53.8 kJ mol −1 more stable than the linear one.…”

On the kinetics of the methanation of carbon dioxide on coprecipitated NiAl(O)

“…Of course, further mechanisms could have been formulated comprising COH or HCOO, respectively (cf. [37][38][39][40] …”

Explicit Water Molecules Play a Key Role in the Mechanism of Rhodium‐Substituted Human Carbonic Anhydrase

“…Research to find alternative ways to produce formic acid is strongly motivated by the fact that formic acid is an ideal hydrogen‐storage material as a result of its volumetric hydrogen density of 5 g of H 2 per liter and because it shows low toxicity and is liquid under ambient conditions. The huge advantages derived from the conversion of CO 2 into formic acid promoted the development of several catalysts based on platinum group transition metals, such as Rh, Ru, and Ir, through homogeneous catalysis or heterogeneous catalysis driven by metal surfaces of Ni or Cu . However, both approaches, in particular the heterogeneous one, showed weaknesses that were mostly derived from the temperature and pressure conditions, which must be high to assist the process .…”