A density functional theory database of hydrogen chemisorption energies on close packed surfaces of a number of transition and noble metals is presented. The bond energies are used to understand the trends in the exchange current for hydrogen evolution. A volcano curve is obtained when measured exchange currents are plotted as a function of the calculated hydrogen adsorption energies and a simple kinetic model is developed to understand the origin of the volcano. The volcano curve is also consistent with Pt being the most efficient electrocatalyst for hydrogen evolution.

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The rate of ammonia synthesis over a nanoparticle ruthenium catalyst can be calculated directly on the basis of a quantum chemical treatment of the problem using density functional theory. We compared the results to measured rates over a ruthenium catalyst supported on magnesium aluminum spinel. When the size distribution of ruthenium particles measured by transmission electron microscopy was used as the link between the catalyst material and the theoretical treatment, the calculated rate was within a factor of 3 to 20 of the experimental rate. This offers hope for computer-based methods in the search for catalysts.

Electrolysis F 4000Trends in the Exchange Current for Hydrogen Evolution. -A DFT based database of hydrogen chemisorption energies on close packed surfaces of a number of transition and noble metals demonstrating the correlation between hydrogen chemisorption energies and the exchange current for hydrogen evolution is given. The obtained volcano curves indicate that Pt is a better electrocatalyst than other metals for hydrogen evolution. The findings can potentially be useful in predicting bimetallic electrocatalysts for hydrogen evolution, as well as for hydrogen electro-oxidation for fuel cell applications. -(NOERSKOV, J. K.; BLIGAARD, T.; LOGADOTTIR, A.; KITCHIN, J. R.; CHEN, J. G.; PANDELOV, S.; STIMMING, U.; J. Electrochem. Soc. 152 (2005) 3, J23-J26; Dep. Phys., Tech. Univ. Den., DK-2800 Lyngby, Den.; Eng.) -W. Pewestorf 24-023

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