Exploiting defects as “chemical reactors” is an exciting concept as the ability to synthesize, manipulate and functionalize defects reaches atomic-scale precision. Defects in materials provide unique atomic-scale motifs, breaking symmetry from the parent lattice structure. Foreign atoms and molecules chemisorb on defects with new conformations and lateral registry creating low energy pathways for heterogeneous catalytic reactions. This IRG will focus on i) Generate model surfaces to study single site, base metal atom / metal oxide support catalysts, and ii) Study single-site, base metal atom / metal oxides for low temp CO/HC oxidation & CO2 reduction.