(392b) From Micro-Kinetics to Macro-Molecules: Understanding the Mechanisms of Polymer Deconstruction

Advances in catalysis have enabled the world to produce and consume more food, energy, and materials. Now, progress in sustainable catalysis is critical to meet growing demands for fuels, polymers, and chemicals without depleting the earth of natural resources and polluting the atmosphere. One of the most pressing modern challenges in sustainability is the overabundance of waste plastics entering landfills and the environment. While chemical re-processing of waste plastics into monomers and petroleum-range hydrocarbons offers a means to keep polymeric carbon in the economy, these processes can require large amounts of energy to dissociate the bonds in plastics and separate useful products. Catalysts with active sites which are tailored to promote desired mechanistic pathways can improve the selectivity and activity of chemical reactions. Professor Alexis Bell has led investigations of many such catalytic reactions, uncovering mechanistic insights and advancements for fields ranging from renewable fuel synthesis, emission control, electrochemical carbon dioxide reduction, and so much more. His work is characterized by rigorous application of chemical engineering fundamentals and clarity which makes the work accessible to the catalysis community. Inspired by this balance of chemical engineering fundamentals, accessibility, and sustainability applications, this talk will discuss how we use kinetic and mechanistic models to advance the catalytic depolymerization of waste plastics to produce value-added chemicals. The talk will start by discussing the challenges associated with polyolefin plastic deconstruction, including both analytical and experimental bottlenecks. Next, the talk will discuss how the use of model compounds for kinetic analysis has inspired technologies for macromolecular deconstruction, and the critical gaps in translating from models to realistic systems. The talk will close with a reflection on Professor Bell’s effective pedagogical approach to research and mentorship, and an outlook for the future of catalysis research and education.