(524a) Catalysis at Excited Interfaces: Insights into Plasma and Plasmonic Chemistry

This presentation will highlight the significance of the humble electron in catalytic transformations while sharing a perspective of how the action of electrons is the main commonality that influences thermal, photo, and electrochemical reactions. Electrons intrinsically have high charge-to-mass ratios and respond significantly to the application of electromagnetic fields through rapid acceleration and, therefore, high kinetic energies. These fields can emerge from incident visible light, through the potential carried within electric fields spanning two (or more) electrodes, or at the boundary between two media with differing dielectric constants (i.e., a heterogeneous catalytic interface). Because electrons have a low mass, the response to these electromagnetic fields can drive far-from-equilibrium states where the electronic temperature can be several thousand degrees higher than the surrounding atoms and molecules. These so-called ‘hot carriers’ can be leveraged to drive non-equilibrium chemical transformation using light and electricity.

This talk will highlight two recent primary discoveries from my laboratory. The first part will emphasize the role of photons in driving collective electronic oscillations, also known as plasmon resonances, in CuPt single-atom alloy nanoparticles and the role of charge localization at Pt dopant sites. In this system, we have observed that active site engineering plays a crucial role in harnessing the true power of the light-driven charge carriers for non-oxidative propane dehydrogenation. In the second part, I will highlight an exciting and emerging frontier in electrochemical transformations – nonthermal plasmas. I will focus on a novel plasma-bubble reactor we have developed, which can achieve direct partial oxidation of methane with 98% methanol liquid-phase selectivity through carefully tuning transport and plasma conditions. Together, these two stories will paint a picture of the importance and shared role of electrons in seemingly divergent catalytic systems and how non-equilibrium states of matter can be harnessed for challenging chemical transformations.