Bridging the temperature and pressure gaps: close-packed transition metal surfaces in anoxygen environment

Abstract

An understanding of the interaction of atoms and molecules with solid surfaces on themicroscopic level is of crucial importance to many, if not most, modern high-tech materialsapplications. Obtaining such accurate, quantitative information has traditionally beenthe realm of surface science experiments, carried out under ultra-high vacuumconditions. Over recent years scientists have realized the importance of obtaining suchknowledge also under the high pressure and temperature conditions under which manyindustrial processes take place, e.g. heterogeneous catalysis, since the materialunder these conditions may be quite different to that under the conditions oftypical surface science experiments. Theoretical studies too have been aimedat bridging the so-called pressure and temperature gaps, and great strides havebeen made in recent years, often in conjunction with experiment. Here we reviewrecent progress in the understanding of the hexagonal close-packed surfaces oflate transition and noble metals in an oxygen environment, which is of relevanceto many heterogeneous catalytic reactions. In many cases it is found that, onexposure to high oxygen pressures and elevated temperatures, thin oxide-likestructures form which may or may not be stable, and which may have little similarityto the bulk oxides, and thus possess unique chemical and physical properties.