EAGER: Nuclear Transmutation in Metal Organic Frameworks through Neutron Absorption

Washington State University, Pullman WA

Investigators

Abstract

With the support of the Chemical Synthesis program in the Division of Chemistry, Qiang Zhang and Zachariah Heiden of Washington State University aim to develop an innovative way to create unique mixed-metal structures in metal-organic frameworks through nuclear transmutation and study their stability under irradiation. Metal-organic frameworks are made by linking metal ions with organic molecules to form structures that can be one, two, or three-dimensional in nature. Such structures can be considered as microscopic scaffolds with holes or pockets. These pockets can be up to 90% of the volume of the structures, which means they are highly porous like a sponge. Traditional methods have struggled to create these structures with specific mixed metal species, but this new transmutation approach could be the key to overcoming this significant limitation. If successful, the materials resulting from this approach are expected to have unique properties that could potentially bring significant advances to various fields such as sensor technology, catalyst development, and materials that can absorb specific substances. A vital aspect of this project is the investigation into how these materials behave under extreme conditions. This knowledge could help in creating materials that can withstand harsh environments such as outer space, or that can improve nuclear waste management. The project will offer unique opportunities for students, particularly those from underrepresented groups, to get hands-on training and experience in porous materials synthesis and nuclear reactor operation under the guidance of Drs. Zhang and Heiden. The funded research aims to apply nuclear transmutation within metal-organic frameworks (MOFs) to introduce secondary metal centers and study their stability under neutron irradiation. The resilience of these new materials under neutron radiation will be rigorously assessed based on their elemental composition, structure, and neutron dose. The level of activated isotopes, which is determined by the neutron dosage, can be controlled by adjusting the neutron irradiation flux while monitoring decay processes. The anticipated consequence of incorporating these secondary metal centers into the MOF structure is a significant alteration in both the stability and electronic properties of the target MOFs. For instance, the introduction of chromium into vanadium MOFs is expected to enhance material stability. The formation of chromium within vanadium MOFs is also expected to alter the electronic properties of the MOF, as the size, acidity and redox chemistry of Cr ions are different from those of the V ions. The project will probe the coordination chemistry and structural dynamics of these materials under neutron flux. This high risk/high potential reward project has the potential to uncover innovative methodologies for developing advanced materials with enhanced properties and functionalities, thereby potentially making a significant contribution to the field of materials science. 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.