Preface: Trends in Computational Catalysis

Computation has continued to grow in significance in the field of catalysis. One routinely sees a wide range of relevant properties computed ranging from adsorption energies and reaction barriers, to full reaction mechanisms, trends across series of catalysts, as well as in developing models of what surfaces might look like under reaction conditions. Computations are performed using density functional theory (DFT), molecular dynamics, kinetic Monte Carlo, and microkinetic models among other approaches. This growth has been spurred by continued development of faster computer hardware, the ready availability of high quality software, and the development of new algorithms and methodologies. In this special issue, we present several current trends in computational catalysis, broadly organized in the areas of (1) adsorption and molecular interactions, (2) kinetics and mechanistic studies, and (3) new methodologies. Complex adsorbates and surfaces are increasingly examined using computational methods. For example, in this issue Sitamraju et al., examined the adsorption of aromatic sulfur-containing molecules on oxide surfaces, and Han examined the subtle interactions of chiral molecules with chiral bimetallic surfaces. In work by Curet-Arana et al., trends in the reaction of CO2 with organometallic molecules were studied. In these three papers, computation provided insight into the nature of the adsorbate–surface or adsorbate-molecule interactions, and provided some insight into how to choose or design materials with desired properties. A growing trend has been the use of DFT calculations to model coverage dependent adsorption properties and to parameterize coarse-grained models such as lattice gas Hamiltonians for use in Monte Carlo simulations. Alfonso illustrates this approach in studying the effects of sulfur poisoning on CO adsorption and shows that in addition to reducing the coverage of CO due to sulfur poisoning, the mobility of CO is dramatically reduced by sulfur poisoning. Kinetic and mechanistic computations have traditionally been fairly expensive compared to computation of adsorption properties. The calculation of reaction barriers and pre-exponential factors remains more expensive than simple adsorption calculations. The continued development of faster and highly parallel computing hardware as well as software enhancement has made many aspects of these calculations routine. It is becoming increasingly common to see studies in reactivity trends of molecules on different surfaces. In this issue, the selectivity in various decomposition pathways of glycerol on Pt(111) are considered by Liu and Greeley, and the decomposition of furan on Pd(111) is considered by Xu. These molecules are significant in biomass-conversion strategies. In a combined experimental and computational study, McCalman et al. consider the reduction of N2O by H2 on Pd catalysts in water, including the effects of adsorbed water molecules in the simulations. The catalyst structures being used in computation continue to grow in complexity. Wei et al. examine the mechanism of the water gas shift reaction over two alloy surfaces using DFT. Balbuena et al. examine effects of segregation and dissolution in fuel cell alloy electrocatalysts using computational methods ranging from DFT to molecular dynamics. Direct computation of properties on nanoparticles is becoming increasingly common. Grabow et al. investigate the synthesis of hydrogen peroxide from hydrogen and oxygen over gold nanoparticles, while Cheng J. Kitchin (&) Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA e-mail: jkitchin@andrew.cmu.edu