Curtiss is author of more than 540 publications. His research has focused on computational chemistry including the development of new quantum chemical methods for accurate energy calculations (G1, G2, G3, and G4 theories) and the application of computational methods to problems in materials science and chemistry including catalysis, batteries, and carbon materials. His recent computational studies have focused on the design of new electrolytes and electrolyte additives for Li-ion batteries, modeling of anode materials for Li-ion batteries, the understanding of charge and discharge chemistries in Li-O2 and Li-S batteries, catalytic reaction mechanisms of supported subnanometer clusters and 2-D materials, and biomass conversion reaction mechanisms. He is also co-inventor of more than 5 patents. He is listed as a Highly Cited Researcher in Chemistry by the Institute for Scientific Information (ISI).