Dr. Aaron Rossini, Department of Chemistry, Iowa State University

The molecular structure of surface species plays a crucial role in both materials science and catalysis. Unfortunately, current techniques for surface characterization often provide an incomplete picture of molecular structure. Solid-state NMR spectroscopy is a powerful technique for characterization of surface species because it is potentially applicable to nearly all the elements of the periodic table and NMR provides precise details about local atomic environments. However, solid-state NMR spectroscopy is limited by poor intrinsic sensitivity. Furthermore, the characterization of surface species is often a considerable challenge because the sites of interest are often dilute. In the past 15 years, fast magic angle spinning (MAS) and dynamic nuclear polarization (DNP) have emerged as techniques to obtain order of magnitude improvements in NMR sensitivity. In this contribution we show how these techniques can be used to accelerate solid-state NMR experiments on surface species and enable NMR experiments with unreceptive and exotic NMR-active nuclei. Surface characterization of a variety of inorganic nanomaterials and heterogeneous catalysts will be demonstrated.

Aaron Rossini completed his PhD studies in September 2010 at the University of Windsor, Windsor, Ontario, Canada, under the supervision of Prof. Robert W. Schurko. In 2011 he moved to Lyon, France to work with Prof. Lyndon Emsley and Dr. Anne Lesage at the Centre de Resonance Magnetique Nucleaire à Très Haut Champs (CRMN Lyon) at the Ecole Normale Superieure de Lyon (ENS Lyon) as a Marie Curie International Incoming Fellow. In October 2014 he moved to École Polytechnique Fédérale de Lausanne (EPFL) in Lausanne, Switzerland to continue working with Prof. Emsley. In August 2015, he moved to Ames, Iowa to join the Department of Chemistry at Iowa State University as an Assistant Professor. He is also affiliated to the US Department of Energy Ames Laboratory as a faculty scientist. He was officially appointed as an Associate Professor with tenure in August 2021.