Collaborative Research: DMREF: Designing Non-conductive Reactive Materials with Mobile Metal Ions

Solid catalytic materials, such as zeolite aluminosilicates, are at the heart of petroleum and natural gas conversion. Some solid catalytically active materials are now known to be dynamic, with metal ions that move throughout the porous solid structures. While this mobility has important influences on the catalytic activity of the zeolite, and therefore the productivity of the industrial process, understanding, quantifying, and tracking this mobility is exceptionally challenging. In this emerging paradigm of dynamic catalytic materials, signals must be identified to track the mobile components and new tools developed to probe their behaviors and contributions to reactivity. This Designing Materials to Revolutionize and Engineer our Future (DMREF) project will investigate the dynamic behavior of technologically-important metal cations such as gallium and copper, dispersed in porous oxide materials. Specifically, the project will explore the spatial extent and timescale for ion mobility, the role of adsorption (determined by the size of the ion and its oxidation state, as well as the nature of the oxide support), the effect of temperature, pressure, protons, and the availability of ligands. Spectroscopic fingerprints for ion mobility will be identified and used to probe their dynamic behavior. Guided by theoretical simulations, these spectroscopic fingerprints will aid in interpreting the measurements and describing the reaction mechanisms. The data and models generated by the project will allow researchers to predict temperature regimes that mark the onset cation mobility, as well as how cation mobility influences catalytic performance, activation during start-up, and deactivation. This will provide insight into how to intentionally synthesize materials with a desired type of dynamic behavior, account for the contributions of mobility to the technological performance of materials, prolong their useful life, and regenerate them by inducing mobility to cause redispersion of the ions. Another important outcome is the training of graduate students and postdoctoral scholars in collaborative research at the intersections of synthesis, spectroscopy, theory and simulations. They will work across disciplines with researchers in the US and abroad, in academia, national labs, and industry, to tackle challenging problems in materials design. 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.