Single-Atom Catalysts on Nanostructure from Science to Applications

Single-atom catalysts (SACs) have attracted many researchers in recent years. Since the demand of global energy and consumption of non-renewable energy all get higher and higher, there are a lot of scientists who put their efforts into developing electrochemical energy conversion through oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and carbon dioxide reduction (CO2RR). SACs also demonstrate powerful and excellent performance in reducing the cost of high activity and selectivity via controlling the surface free energy and the specific activity per metal atom over metal particle size and the effects of the support in stabilizing single-atom. SACs are considered as an attractive and powerful technique that can enhance catalytic activity and selectivity, which contain isolated individual atoms dispersed on the surface of appropriated supports. Decreasing/minimizing the size of a metal particle to a single metal atom can maximize the atomic efficiency of metals as well as increase its specific activity performance by increasing the free surface energy. Single metal atoms have the smallest size of metals, which means single metal atoms have huge free surface energy. Many advanced studies have revealed excellent activity, selectivity, and stability of SACs. This chapter presents the cases and applications of single-atom catalysis from the basic mechanism and summarizes the advantages of SACs with the perspective for water splitting and CO2RR.