Understanding and predicting the performance of metal exchanged SSZ-13 zeolite in the conversion of methane to methanol

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Vast reserves of shale gas are now being accessed around the globe. Shale gas is mostly methane, which is difficult to transport and of relatively low value. The conversion of methane into higher value products, such as methanol, requires new and improved catalytic processes. Methanol is a platform chemical, with existing technologies for transforming it into a variety of useful, important products. Metal exchanged zeolites are a class of materials showing great promise as catalysts for transforming methane to methanol. However, how these catalysts work is not yet well-understood. Further, their catalytic performance depends on many complex parameters which are difficult to optimize. In this project, Dr. Mavrikakis of the University of Wisconsin is using both theory and experiments to understand the performance of one specific zeolite structure, known as SSZ-13, for the conversion of methane to methanol. His work is developing a correlation between zeolite synthesis conditions and the resulting chemical composition of SSZ-13, and between its catalytic performance and reaction conditions. The insights gained are being used to design experimental synthesis protocol to produce the ideal zeolite catalyst and reaction conditions for methane conversion to methanol. During this project Dr. Mavrikakis is informing the public about the importance of theoretical modeling in fundamental and industrial research and practice. Dr. Mavrikakis is also educating undergraduate students about communicating science to middle school and high school students, as well as providing internships to undergraduate students to conduct research in his group. With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Mavrikakis at the University of Wisconsin - Madison is applying a combined theoretical/experimental approach for understanding the fundamentals of converting methane to methanol using transition metal exchanged SSZ-13 zeolite. This includes: (i) first-principles modeling of zeolite synthesis through the development of correlations between synthesis parameters, such as the identity of template and ions present, and the obtained zeolite structure, such as the local Al distribution and defect density; (ii) the ab-initio calculation of phase diagrams for different transition metals (Cu, Fe, Co, Ni) and types of active sites for a wide range of operating conditions, and (iii) the calculation of reaction pathways for the most stable active catalytic sites. In a subsequent step, this information is being used to develop a protocol for the experimental synthesis, elemental composition and reaction conditions for maximized performance of the ideal metal exchanged SSZ-13 zeolite for the conversion of methane to methanol. In parallel, and in collaboration with the Wisconsin Institute for Chemical Education, Dr. Mavrikakis' group is developing modules to teach undergraduate and middle school students how thinking at the molecular level can lead to new powerful technologies. Furthermore, the P.I. is participating in the Research Experience for Undergraduates program at UW Madison, which is providing hands-on research experiences to undergraduate researchers with a focus on female students and students from underrepresented groups. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.