Single Atom Catalysts: Design, Synthesis, Characterization, and Applications in Energy focuses on the synthesis, design, and advanced characterization techniques for single-atom catalyst (SAC) materials and their direct energy conversion and storage applications. This book reviews the emerging applications of SACs in fuel cells, batteries, water splitting, carbon dioxide reduction, and nitrogen fixation. Both noble metal and non-noble metal SACs are discussed, as noble metal-based SACs are highly efficient while non-noble metal-based SACs might have lower associated costs. There is an emphasis on materials' design focused on improving the performance of catalysts based on overall catalytic activity, selectivity, and stability. Specific parameters that impact this performance are emphasized throughout the book, including single-metal atom stabilization, metal-support interactions, and the coordination environment.