Thermodynamics of hydrogen adsorption on ruthenium fcc surfaces: a density functional theory study
Marietjie J Ungerer1,2, Nora H de Leeuw2,3
1School of Chemistry, Cardiff University, Cardiff CF10 3AT, UK.
Abstract:
Within the framework of the application of liquid organic hydrogen carriers (LOHC) to store, transport and re-generate hydrogen, ruthenium (Ru) is by far the most widely used catalyst. In its natural bulk state, the most abundant phase observed is the hexagonal close-packed (hcp) phase, but experimental studies on nanoparticles have shown that the face-centred cubic (fcc) phases are also present and are highly active in catalytic reactions. In this study, we have carried out calculations based on the density functional theory, with the generalized gradient approximation and long-range dispersion corrections, to investigate the behaviour of hydrogen adsorption at the fcc Ru (001), (011) and (111) surfaces. The Ru surfaces have been covered systematically with hydrogen (H), with a focus on the geometries, stabilities and adsorption energies. A detailed analysis has been performed of the energetic and electronic properties of a hydrogen monolayer on the Ru surfaces, combined with a thermodynamic analysis of the effect of temperature and pressure on the surface coverage, where the highest surface coverage observed was on the Ru (001) and (011) surfaces. The results indicate that the dissociation of H2 occurs readily and that the adsorption energies of single H atoms are between 0.4 and 0.6 eV. Neither recombination of H atoms to form molecular hydrogen (H2) or surface poisoning was observed.
More Related Videos
Related Concept Videos
Reduction of Alkenes: Catalytic Hydrogenation
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Hess's Law
Electrophilic Addition of HX to 1,3-Butadiene: Thermodynamic vs Kinetic Control
Radical Anti-Markovnikov Addition to Alkenes: Thermodynamics
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation


