Rolf Jürgen Behm

Bio: Rolf Jürgen Behm is an academic researcher from University of Ulm. The author has contributed to research in topics: Scanning tunneling microscope & Catalysis. The author has an hindex of 86, co-authored 446 publications receiving 29067 citations. Previous affiliations of Rolf Jürgen Behm include IBM & Lawrence Berkeley National Laboratory.

Scanning tunneling microscopy observations on the reconstructed Au(111) surface: Atomic structure, long-range superstructure, rotational domains, and surface defects

Abstract: Keywords: Surface Electronic and Atomic Structure ; Spectroscopy ; Spin-Polarized STM Reference LNS-ARTICLE-1990-002doi:10.1103/PhysRevB.42.9307 Record created on 2009-04-14, modified on 2017-05-12

Characterization of High‐Surface‐Area Electrocatalysts Using a Rotating Disk Electrode Configuration

Abstract: A newly developed method is presented which allows the characterization of the electrocatalytic properties of highly dispersed electrocatalysts in a true rotating disk electrode (RDE) configuration by attaching the catalyst powder on a glossy carbon electrode via a thin Nafion film. Complete utilization and high reproducibility of both the electrode preparation and the catalyst loading could be shown via voltammetry and CO stripping voltammetry. Furthermore RDE measurements on the electro‐oxidation of hydrogen on Pt/Vulcan showed that the effect of diffusion through the Nation film can be avoided by proper electrode preparation. Therefore, the electrode kinetics for fuel cell relevant reactions under continuous flow conditions can be measured directly without mathematical modeling.

Electric Field Effect in Atomically Thin Carbon Films

Abstract: We describe monocrystalline graphitic films, which are a few atoms thick but are nonetheless stable under ambient conditions, metallic, and of remarkably high quality. The films are found to be a two-dimensional semimetal with a tiny overlap between valence and conductance bands, and they exhibit a strong ambipolar electric field effect such that electrons and holes in concentrations up to 10 13 per square centimeter and with room-temperature mobilities of ∼10,000 square centimeters per volt-second can be induced by applying gate voltage.

The rise of graphene

Abstract: Graphene is a rapidly rising star on the horizon of materials science and condensed-matter physics. This strictly two-dimensional material exhibits exceptionally high crystal and electronic quality, and, despite its short history, has already revealed a cornucopia of new physics and potential applications, which are briefly discussed here. Whereas one can be certain of the realness of applications only when commercial products appear, graphene no longer requires any further proof of its importance in terms of fundamental physics. Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena, some of which are unobservable in high-energy physics, can now be mimicked and tested in table-top experiments. More generally, graphene represents a conceptually new class of materials that are only one atom thick, and, on this basis, offers new inroads into low-dimensional physics that has never ceased to surprise and continues to provide a fertile ground for applications.

Nanostructured materials for advanced energy conversion and storage devices

Abstract: New materials hold the key to fundamental advances in energy conversion and storage, both of which are vital in order to meet the challenge of global warming and the finite nature of fossil fuels. Nanomaterials in particular offer unique properties or combinations of properties as electrodes and electrolytes in a range of energy devices. This review describes some recent developments in the discovery of nanoelectrolytes and nanoelectrodes for lithium batteries, fuel cells and supercapacitors. The advantages and disadvantages of the nanoscale in materials design for such devices are highlighted.

Origin of the Overpotential for Oxygen Reduction at a Fuel-Cell Cathode

Abstract: We present a method for calculating the stability of reaction intermediates of electrochemical processes on the basis of electronic structure calculations. We used that method in combination with detailed density functional calculations to develop a detailed description of the free-energy landscape of the electrochemical oxygen reduction reaction over Pt(111) as a function of applied bias. This allowed us to identify the origin of the overpotential found for this reaction. Adsorbed oxygen and hydroxyl are found to be very stable intermediates at potentials close to equilibrium, and the calculated rate constant for the activated proton/electron transfer to adsorbed oxygen or hydroxyl can account quantitatively for the observed kinetics. On the basis of a database of calculated oxygen and hydroxyl adsorption energies, the trends in the oxygen reduction rate for a large number of different transition and noble metals can be accounted for. Alternative reaction mechanisms involving proton/electron transfer to ...