AFM and STM Studies of Model and Microfabricated Catalysts

点击翻译按钮获取中文摘要

Techniques using atomic force microscopy (AFM) and scanning tunnelling microscopy (STM) are applied to the investigation of platinum and palladium model catalysts. These methods were developed during the previous grant to this laboratory. Three types of systems are studied: single crystals, ultrathin films, and microfabricated model catalysts prepared by techniques used in microelectronic device fabrication; the last is an attempt to control the particle size and morphology of a supported catalyst. Catalytic activity and selectivity of these catalysts is measured for the hydrogenation of 1,3 - butadiene. Adsorbed species are studied with infrared spectroscopy. An attempt is made to describe the active sites and to correlate physical and chemical features with activity and selectivity. This is a test of the utility of these new methods in catalyst characterization and design. The methods are capable of a very high degree of resolution that may (or may not) be helpful in understanding practical systems.