selectivity, and stability. To achieve this goal it is often necessary to characterize catalyst composition and structure at the atomic level. Ultimately, it is most desirable to identify and characterize the catalytic site at the atomic level. Because many catalysts are known to undergo physical and chemical changes under reaction conditions, catalyst characterization should preferably be carried out in situ, or at least under conditions relevant to actual catalytic processes. Knowledge of the interactions between a catalyst and reactants, intermediates, and products is needed to understand the influence of the catalyst on the structure and bonding of species involved in catalyzed reactions. The dynamics of chemical transformations occurring under the influence of the catalyst is yet another area in which information is needed.
The development of new or improved catalysts is complex, involving extensive testing and evaluation. Because the range of variables is often very large, and the relationships between changes in these variables and catalyst performance are often not clearly identified, catalyst development can be a tedious and expensive task. Knowledge derived from scientific studies provides a basis for conceiving new catalysts and catalytic reactions, and for interpreting the results of experimental observation. Moreover, many of the analytical techniques developed in the pursuit of catalytic science can be used effectively to elucidate cause-effect relationships and, thereby, to accelerate the process of catalyst development.
Opportunities for advancing the frontiers of catalytic science exist in four areas: the synthesis of new classes of catalytic materials, catalyst characterization, the mechanism and dynamics of catalytic reactions, and the theory of catalysis. Each of these areas is highlighted below, with indications given for future research directions.
There are three reasons for pursuing research on the synthesis of catalytic materials. The first is to find new or improved catalysts for a desired reaction (e.g., efficient production of high-quality fuels, the decomposition of nitric oxide, the direct conversion of methane to methanol, the synthesis of homochiral or enantiomerically pure drugs). In this instance, either new classes of materials or modifications of existing materials are sought to achieve the desired increase in activity or selectivity. The second reason for studying catalyst synthesis is to establish the relationships between preparative procedure and final catalyst structure and properties. The objective in this case is to understand how the choice of starting materials and synthesis conditions influences catalyst composition and structure. Success in this endeavor can lead to the identification of principles and strategies for preparing catalysts with specified properties. The third reason