The 37th Annual Charles A. Coulson Lecture: Reactions and Interactions in Complex Chemical Systems

Systems of chemical reactions are central to a wide range of technological and environmental questions, such as autoignition in combustion engines, heterogeneous catalysis, or formation of atmospheric aerosols. Understanding the details of these systems requires knowledge of not only the individual reaction steps but also the way these steps interact in the web of chemical transformations. 

At the Combustion Research Facility (CRF) at Sandia National Laboratories, research groups employ a range of experimental and theoretical tools to probe chemical reactions and sets of reactions. One central focus is the experimental characterization and quantification of reaction intermediates. I will describe some of the approaches CRF researchers take to accomplish this. I will focus in more detail on recent work that relates to hydrocarbon oxidation chemistry in the troposphere and in combustion. 

First, I will discuss measurements of the reactivity of difficult-to-access intermediate species, like the carbonyl oxide Criegee intermediate that plays a key role in the network of reactions that describes ozone-initiated of hydrocarbons in Earth’s troposphere. Synchrotron photoionization mass spectrometry is used to characterize reactions of these intermediates and their products. Second, a reaction with energized products of exothermic reactions can follow a different course than the reaction would under thermal conditions. I will highlight how the combination of advanced theory and modeling with quantitative measurements of time-dependent species concentrations in laser-initiated reactions can teach us about linked sequences of reactions in autoignition chemistry. 

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the United States Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

About the Speaker

Dr. Craig Taatjes is senior manager for Physical Sciences at Sandia National Laboratories in Livermore, California, overseeing departments that conduct basic research covering a wide range of experimental and theoretical physics and chemistry. His own research has been aimed at understanding fundamental kinetics of chemical reactions that are central to solutions for transportation energy and for modeling atmospheric oxidation processes that could affect Earth’s radiation balance. 

Dr. Taatjes earned a Ph.D. in chemical physics from the University of Colorado, Boulder and a BS in chemistry from Calvin College (now Calvin University). He is the Editor-inChief for the journal International Journal of Chemical Kinetics and was a visiting fellow of Joint Institute for Laboratory Astrophysics (JILA) and a Benjamin Meaker visiting professor at the University of Bristol. Dr. Taatjes is a Polanyi Medal Recipient (2014, Royal Society of Chemistry), a two-time David A. Shirley Award Recipient (Advanced Light Source, Lawrence Berkeley National Laboratory), O.W. Adams Award Recipient (Sandia Combustion Research Facility) for outstanding achievement in combustion science, Lockheed Martin NOVA award winner for Individual Technical Excellence, Fellow of the Combustion Institute, and a Fellow of the American Physical Society.