AFM and STM Studies of Model and Microfabricated Catalysts

原子力显微镜(AFM)和扫描隧道显微镜(STM)技术被应用于铂和钯模型催化剂的研究。这些方法是在上一次给这个实验室的资助期间开发出来的。研究了三种体系：单晶系、超薄膜系和微电子器件制备技术制备的微细模型催化剂；最后一类是尝试控制负载型催化剂的颗粒大小和形貌。考察了这些催化剂对1，3-丁二烯加氢反应的催化活性和选择性。用红外光谱对吸附物种进行了研究。试图描述活性中心，并将物理和化学特征与活性和选择性联系起来。这是对这些新方法在催化剂表征和设计中的实用性的一次测试。这些方法具有非常高的分辨率，这对理解实际系统可能(也可能不)有帮助。

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.