Over the past decade the theoretical description of surface reactions has undergone a radical development. Advances in density functional theory mean it is now possible to describe catalytic reactions at surfaces with the detail and accuracy required for computational results to compare favourably with experiments. Theoretical methods can be used to describe surface chemical reactions in detail and to understand variations in catalytic activity from one catalyst to another. Here, we review the first steps towards using computational methods to design new catalysts. Examples include screening for catalysts with increased activity and catalysts with improved selectivity. We discuss how, in the future, such methods may be used to engineer the electronic structure of the active surface by changing its composition and structure.

Towards the computational design of solid catalysts

There is a special reason for reviewing this book at this time: it is the 50th edition of a compendium that is known and used frequently in most chemical and physical laboratories in many parts of the world. Surely, a publication that has been published for 56 years, withstanding the vagaries of science in this century, must have had something to offer. There is another reason: while the book is a standard fixture in most chemical and physical laboratories, including those in medical centers, it is not as frequently seen in the laboratories of physician's offices (those either in solo or group practice). I believe that the Handbook can be useful in those laboratories. One of the reasons, among others, is that the various basic items of information it offers may be helpful in new tests, either physical or chemical, which are continuously being published. The basic information may relate

Handbook of Chemistry and Physics

During the past decade, computer simulations based on a quantum-mechanical description of the interactions between electrons and between electrons and atomic nuclei have developed an increasingly important impact on solid-state physics and chemistry and on materials science—promoting not only a deeper understanding, but also the possibility to contribute significantly to materials design for future technologies. This development is based on two important columns: (i) The improved description of electronic many-body effects within density-functional theory (DFT) and the upcoming post-DFT methods. (ii) The implementation of the new functionals and many-body techniques within highly efficient, stable, and versatile computer codes, which allow to exploit the potential of modern computer architectures. In this review, I discuss the implementation of various DFT functionals [local-density approximation (LDA), generalized gradient approximation (GGA), meta-GGA, hybrid functional mixing DFT, and exact (Hartree-Fock) exchange] and post-DFT approaches [DFT + U for strong electronic correlations in narrow bands, many-body perturbation theory (GW) for quasiparticle spectra, dynamical correlation effects via the adiabatic-connection fluctuation-dissipation theorem (AC-FDT)] in the Vienna ab initio simulation package VASP. VASP is a plane-wave all-electron code using the projector-augmented wave method to describe the electron-core interaction. The code uses fast iterative techniques for the diagonalization of the DFT Hamiltonian and allows to perform total-energy calculations and structural optimizations for systems with thousands of atoms and ab initio molecular dynamics simulations for ensembles with a few hundred atoms extending over several tens of ps. Applications in many different areas (structure and phase stability, mechanical and dynamical properties, liquids, glasses and quasicrystals, magnetism and magnetic nanostructures, semiconductors and insulators, surfaces, interfaces and thin films, chemical reactions, and catalysis) are reviewed. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008

Ab-initio simulations of materials using VASP: Density-functional theory and beyond.

The fuel cell is a promising alternative to environmentally unfriendly devices that are currently powered by fossil fuels. In the polymer electrolyte membrane fuel cell (PEMFC),the main fuel is hydrogen,which through its reaction with oxygen produces electricity with water as the only by-product. To make PEMFCs economically viable,there are several problems that should be solved; the main one is to find more effective catalysts than Pt for the oxygen reduction reaction (ORR),1/2 O 2 + 2H + + 2e = H2O. The design of inexpensive,stable,and catalytically active materials for the ORR will require fundamental breakthroughs,and to this end it is important to develop a fundamental understanding of the catalytic process on different materials. Herein,we describe how variations in the electronic structure determine trends in the catalytic activity of the ORR across the periodic table. We show that Pt alloys involving 3d metals are better catalysts than Pt because the electronic structure of the Pt atoms in the surface of these alloys has been modified slightly. With this understanding,we hope that electrocatalysts can begin to be designed on the basis of fundamental insight.

Changing the Activity of Electrocatalysts for Oxygen Reduction by Tuning the Surface Electronic Structure

http://www.ibmc.up.pt/projectos/FJMonteiro/Bonamidi%20Project/References%20Bonamidi/Denry%20-%20State%20of%20the%20art%20zirconia%20dental%20applications.pdf

State of the art of zirconia for dental applications

We have studied the trends in CO adsorption on close-packed metal surfaces: Co, Ni, Cu from the 3d row, Ru, Rh, Pd, Ag from the 4d row and Ir, Pt, Au from the 5d row using density functional theory. In particular, we were concerned with the trends in adsorption energy, geometry, vibrational properties and other parameters derived from the electronic structure of the substrate. The influence of specific changes in our set-up, such as choice of the exchange correlation functional, the choice of pseudopotential, size of the basis set and substrate relaxation, has been carefully evaluated. We found that, while the geometrical and vibrational properties of the adsorbate–substrate complex are calculated with high accuracy, the adsorption energies calculated with the gradient-corrected Perdew–Wang exchange–correlation energies are overestimated. In addition, the calculations tend to favour adsorption sites with higher coordination, resulting in the prediction of the wrong adsorption sites for the Rh, Pt and Cu surfaces (hollow instead of top). The revised Perdew–Burke–Erzernhof functional (RPBE) leads to lower (i.e. more realistic) adsorption energies for transition metals, but to the wrong results for noble metals—for Ag and Au, endothermic adsorption is predicted. The site preference remains the same. We discuss trends in relation to the electronic structure of the substrate across the periodic table, summarizing the state-of-the-art of CO adsorption on close-packed metal surfaces.

https://iopscience.iop.org/article/10.1088/0953-8984/16/8/001/pdf

CO adsorption on close-packed transition and noble metal surfaces: trends from ab initio calculations

We have studied the trends in CO adsorption on close-packed metal surfaces: Co, Ni, Cu from the 3d row, Ru, Rh, Pd, Ag from the 4d row and Ir, Pt, Au from the 5d row using density functional theory. In particular, we were concerned with the trends in the adsorption energy, the geometry, the vibrational properties and other parameters derived from the electronic structure of the substrate. The influence of specific changes in our setup such as choice of the exchange correlation functional, the choice of pseudopotential and size of the basis set, substrate relaxation has been carefully evaluated. We found that while the geometrical and vibrational properties of the adsorbate-substrate complex are calculated with high accuracy, the adsorption energies calculated with the gradient-corrected Perdew-Wang exchange-correlation energies are overestimated. In addition, the calculations tend to favour adsorption sites with higher coordination, resulting in the prediction of wrong adsorption sites for the Rh, Pt and Cu surfaces (hollow instead of top). The revised Perdew-Burke-Erzernhof functional (RPBE) leads to lower (i.e. more realistic) adsorption energies for transition metals, but to wrong results for noble metals - for Ag and Au endothermic adsorption is predicted. The site preference remains the same. We discuss trends in relation to the electronic structure of the substrate across the Periodic Table, summarizing the state-of-the-art of CO adsorption on close-packed metal surfaces.

CO adsorption on close-packed transition and noble metal surfaces: Trends from ab-initio calculations

The dissociative adsorption of oxygen on the (111) surfaces of platinum, palladium, and nickel has been investigated using ab initio local-spin-density calculations. For all three surfaces, adsorption is shown to be precursor-mediated and the structural, energetic, vibrational and electronic properties of the precursors are in very good agreement with the available experimental information. The investigation of the transition states shows that on Pt and Pd the barriers for dissociation are comparable to (or at sufficiently high coverage even higher than) the desorption barriers. In combination with large energies for atomic adsorption, this also leads to a high barrier for associative desorption---in agreement with observation. In contrast, the dissociation barrier for ${\mathrm{O}}_{2}$ on Ni(111) is low and occurs already for a less stretched molecule. The trends in molecular and atomic adsorption and in the dissociation barriers are discussed in relation to the geometric and electronic properties of the substrate and to the sticking probabilities observed in molecular-beam experiments.

Precursor-mediated adsorption of oxygen on the (111) surfaces of platinum-group metals

CO oxidation on transition metal surfaces: reaction rates from first principles

Zirconia is of great industrial importance as support for catalysts and as ion conductor. Especially when mechanical stability is needed in environments with varying temperature the tetragonal modification is superior, because of its high resistivity against physical shocks and thermal stresses. In this study density functional theory is used to investigate the interaction between Y impurities and oxygen vacancies and to develop in this way a structural model for Y-doped zirconia. For every two Y defects an O vacancy is formed at a distance of about $4.11 \AA{}$ to each dopant. An activation energy for ion conductivity of 0.87 eV is calculated in very good agreement with experimental findings.

A. Eichler

Papers

CO adsorption on close-packed transition and noble metal surfaces: trends from ab initio calculations

CO adsorption on close-packed transition and noble metal surfaces: Trends from ab-initio calculations

Precursor-mediated adsorption of oxygen on the (111) surfaces of platinum-group metals

CO oxidation on transition metal surfaces: reaction rates from first principles

Tetragonal Y-doped zirconia: Structure and ion conductivity.