Model in Heterogeneous Catalysis: Surface Science Quo Vadis?

Abstract

Model catalyst systems have been prepared by growth of small metal aggregates on thin well ordered oxide films of alumina and silica. These systems lend themselves to structural and morphological characterization via scanning probe microscopies and transmission electron microscopy and bridge to a certain extent the materials gap between metal single crystal studies and the investigation of real catalyst samples. Recently, the classical surface science techniques applied under ultrahigh vacuum conditions have been augmented by non-linear optical techniques, such as sum frequency generation, which can also be applied under ambient gas pressures. Thus, the pressure gap between studies in surface science under realistic conditions can be bridged.

Catalytic reactions on platinum nanofacets: bridging the size and complexity gap

“…alumina) films as substrates for the metal cluster deposition. The quasi two-dimensional systems prepared that way can be well characterised morphologically by surface analytic techniques [1][2][3] and eventually subjected to an in situ kinetic investigation [4].…”

Shape-dependence of the thermal and photochemical reactions of methanol on nanocrystalline anatase TiO2

“…While this approach has been very successful, it still has its limitations since single crystals often do not contain the range of sites that occur in the analogous high surface area catalysts that are used in industrial practice. Recently studies have started to appear in the literature in which an effort has been made to bridge this so called "materials gap" [5][6][7][8][9][10][11][12]. One promising approach to achieving this goal is use thin films of well-defined nanocrystals as model catalysts.…”

Ultrathin Oxide Films

“…Since the tools frequently used to study heterogeneous catalysts are limited in their ability to reveal details of oxide surface structure/properties, the atomic-level techniques of surface science offer numerous advantages as alternative investigative procedures, providing useful insights into the physics and chemistry of oxide surfaces [2][3][4][5][6]. Included in this review is the interaction of these oxide surfaces with molecules from the gas phase, followed by the interaction of oxide surfaces with metal and metal oxide deposits, and how these composite systems interact with gas-phase reactants [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. In this chapter we concentrate on recent developments in the investigations of thin oxide films supported on metal single crystals.…”