Principal Investigator: John T. Gleaves
Institution: Washington University
Mixed metal oxides (MMO) are widely used as catalysts in the petroleum, chemical, environmental, and pharmaceutical industries. A controlling factor in catalyst performance is the concentration of oxygen and metal species in the MMO surface. Industrial MMO catalysts are prepared by bulk techniques, which provide limited control of surface properties. Samples with the same bulk crystal structure and composition can exhibit different performance when prepared by different routes. This difference may be attributed to a change in the surface concentration of one or more of the catalyst constituents. This GOALI research project will establish a new method of adding atoms to the surface of bulk catalytic materials while maintaining the same bulk composition, and charting the change in catalytic properties as the surface is heated or exposed to a reactant mixture. This new process, dubbed "atomic tailoring", will be used to develop highly selective and active catalysts for the partial oxidation of propane to acrylic acid. Atomic beam deposition, a technique used in surface science, has been adapted so that metal atoms (including those with high melting points) can be directly deposited on particles. After deposition, special vacuum transient response experiments (called TAP experiments) will be used to monitor catalytic properties as the modified material is heated and exposed to a reactant atmosphere.
Improved catalysts for propane conversion to acrylic acid will allow propane to replace propene as a feedstock. The lower feedstock cost for propane, coupled with reduced capital afforded by a direct rather than two-step process, will lower production costs by 20-25%. The knowledge gained from fabricating more active and selective partial oxidation catalysts for propane will be applicable to other selective oxidation reactions, especially reactions of other alkanes. From a U.S. economic and environmental perspective, the development of new catalysts for alkane activation and selective oxidation to commercially useful products will deliver energy savings of up to 37 trillion BTUs/yr and will significantly reduce the generation of green-house gases. Published results from this study will also be useful to other researchers who are designing experiments to probe molecular level processes on complex catalytic surfaces. This GOALI program will introduce graduate and undergraduate students to exciting real-world problems that when solved will have a significant economic, social, and environmental impact. Students will work as part of a diverse team, and they will gain hands-on experience designing, building, and running complex experiments that define the state of the art. The program strongly encourages minority and female students to become involved in research while still encouraging all undergraduates to pursue advanced degrees. Graduate and undergraduate students will work with industrial researchers at an industrial laboratory and will have the opportunity to present their work at academic-industrial group meetings and at national scientific meetings.
