Thuy-Ai (Bi) Ngyuen

Thuy-Ai (Bi) Ngyuen
2016 Mellichamp Sustainability Fellow

Research

Bottom-up Assembly of Copper Nanoclusters for Use as CO2 Reduction Catalysts

Atomically precise, noble metal nanoclusters (NCs) smaller than ~2 nm in diameter are an emerging area of nanoscience with potential applications in catalysis, medicine, and imaging. There are now many structurally characterized NCs of Au and Ag in the literature, while comparable copper NCs are rare. This is partially due to the enhanced stability of Cu(I) versus Au(I) and Ag(I), making it more challenging to generate Cu(0)-containing NCs. There is significant interest in studying copper because it is an earth abundant first row metal and its use in new technologies could reduce our dependence on critical metals. In addition, there is precedent for using copper for COreduction as it is the only transition metal catalyst that favors the notoriously difficult formation of desirable C2 hydrocarbons in the electrochemical reduction of CO2 and new developments indicate that metallic copper electro-catalyst nanomaterials can reduce CO2 to ethylene, often with lower over-potentials, better stability and higher selectivity than their polycrystalline counterparts. We have been exploring routes to systematically control composition and morphology of well-defined, mono-disperse copper NCs and superatoms. Understanding the mechanisms of NC formation and growth is both of fundamental interest and a necessity for the tailoring of nanocluster structures and properties. The broad range of spectroscopic techniques, including X-ray diffraction, neutron diffraction, and XAS, in conjunction with kinetic and catalytic screening that we have access to through collaborations will yield unique insights into structure-function relationships. These results will guide the methodology needed for the rational syntheses of nanomaterials using elements from across the periodic table. 

Advisor:  Trevor Hayton