CAS: Synthesis and Reactivity of Oxygen-atom Vacancies in Molecular Vanadium Oxide Assemblies

University Of Rochester, Rochester NY

Investigators

Abstract

With the support of the Chemical Synthesis program in the Division of Chemistry, Ellen Matson of the University of Rochester will study the synthesis and reactivity of oxygen-atom vacancies at the surface of vanadium oxide clusters. In considering the global challenges society faces today, the issue of securing future energy resources is particularly conspicuous. As fossil fuels are depleted, chemists have turned their focus to investigating synthetic methods for the conversion of abundant greenhouse gases into energy-rich chemical fuels. A central challenge to developing sustainable and renewable fuel production strategies is the activation of these small molecules. Industrially, solid-state metal oxide catalysts have been shown effective for the mediation of small molecule activation reactions (e.g., the reduction of CO2 to methanol). Reactive metal ions, accessed through the loss of an oxygen atom from the surface of the material, have been proposed to participate in small molecule activation reactions. To elucidate properties of multimetallic systems that inform the surface reactivity of these materials, the Matson Laboratory will study how the elemental composition of vanadium oxide clusters translates to the propensity of oxygen-atoms to be removed from the assembly. These studies will aid in the elucidation of design criteria of superior catalysts for the production of chemical fuels. Dr. Matson will continue to provide leadership in a campus-wide effort to improve diversity, equity, and inclusion in science, technology, engineering, and mathematics (STEM) departments, and in organizing the Western New York Symposium in inorganic chemistry. This project aims to develop and study the synthesis and reactivity of oxygen-atom vacancies at the surface of vanadium oxide clusters. Oxygen-atom vacancies at the surface of heterogeneous, reducible metal oxides play a critical role in the conversion of inert, energy-poor substrates to energy-rich chemical fuels. Understanding the mechanism(s) by which these defect sites form, and the structure-function relationships that define the generation and reactivity of O-atom vacancies, will provide a template for the strategic design of materials with enhanced activity. During the funding period, Matson will study new schemes for the formation of oxygen-atom defects at the surface of polyoxovanadate-alkoxide clusters. Subsequently, Matson will investigate the role cation- and anion-dopants, as well as surface ligands, play in modulating the formation of oxygen-atom vacancies at the surface of the assembly. Characterization of all complexes will be performed via 1H NMR, infrared, and electronic absorption spectroscopy, as well as electrospray ionization mass spectrometry and single crystal X-ray diffraction. Additional kinetic analysis will provide insight into mechanisms and activation parameters associated with oxygen-atom vacancy formation at the surface of the cluster. 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.