CEE Seminar - Toward Single Atom Catalysis for Environmental Application

Presenter: Prof. Jaehong Kim, School of Engineering and Applied Science, Yale University

Various noble metals have been employed as catalysts and co-catalysts to enhance the kinetics of reactions that are critical for environmental remediation. The need to maximize the available catalytic sites per unit mass, particularly due to noble metal scarcity and high cost, as well as the unique material properties manifested at nanoscale, has driven the development of material architectures at the nanoscale. Recent theoretical and experimental studies have explored metal catalysts on sub-nanometer, atomic scale to maximize atomic efficiency. A single-atom catalyst (SAC) is the theoretical limit in this endeavor, and previous studies have identified additional benefits such as low coordination state and strong interaction with the surrounding substrate resulting in selective catalysis with enhanced activities. For past few years, our group has since been exploring various SACs (Pt, Pd, Fe, Co, Cu, etc.) anchored on different substrates (SiC, C3N4, TiO2, and carbon) that exhibit unique catalytic properties. This talk summarizes our recent and currently on-going studies to advance the water treatment catalysts from the nano-scale toward the single atom scale such as: (1) single-atom Pt and Pd anchored to SiC for selective hydrogenation of halogenated organic pollutants; (2) single-atom Pd alloyed with Cu for thermocatalytic and electrocatalytic nitrate reduction; (3) spatial separation of two co-catalysts by coordinating single atom cobalt at the void center of C3N4 and anchoring anthraquinone at the edges of C3N4 platelets to enhance the catalytic synthesis of H2O2, a precursor chemical for advanced oxidation; (4) loading Co single atoms onto layered graphene oxide membrane to achieve advanced oxidation during high pressure filtration; and (5) challenges associated with the stability of single atoms during water treatment environment.