Single-atom catalysts (SACs), which are actually metal atoms scattered on the atomic level, with high catalytic performance, have shown different chemical reactions. By combining the characteristics of heterogeneous and homogeneous catalysts, SACs as a type of Heterogeneous catalyst are considered unique. The study of single-atom electrocatalysts for accelerating slow kinetics of electrochemical reactions with high efficiency and low cost is very important. However, the design and synthesis of SACs on solid bases with high activity, stability, and selectivity remain a major challenge. So far single atom catalysts in various fields have been used especially in electrocatalytic processes and energy storage systems. New SACs have been synthesized that have excellent electrocatalytic performance with high efficiency in different acidic or alkaline environments. Among the reactions which use this electrocatalyst, are the hydrogen evolution reaction (HER) and the
oxygen reduction reaction (ORR), and the oxygen evolution reaction (OER) [۱]. To choose the desired single atom, transition metals with high melting and boiling points, high strength, and excellent electrical and thermal conductivity are suitable options. However, due to the high surface energy and low coordination environment of individual metals, SACs always accumulate over time and this leads to a loss of activity and stability. In addition, catalysts based on noble metals, show high catalytic activity, but high cost, and poor stability, seriously restricting their large-scale production and limiting their practical application. As an alternative, readily available, affordable non-precious metal-based catalysts (NPMCs) are economical and very active and have many advantages for electrocatalytic reactions [۲]. On the other hand, a suitable base can effectively increase the stability of SACs under harsh catalytic conditions. Many bases including metal surfaces, oxides, chlorides, hydroxides, carbides, nitrides, metal sulfides and phosphides, double hydroxides Layers of one, two, or three-dimensional carbon materials (LDH), zeolites, metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and polymers can be used. Among them, MOFs are the most promising precursors for the synthesis of several SACs in recent years. Due to well-defined pore structures and highly regular arrangements of metal nodes and organic bonds, they can flexibly introduce metal sites into MOFs followed by a thermal or chemical conversion process. Also, by forming coordination bonds of carbon with elements such as S, N, and P, more stability of SACs is achieved. A strategy is a facile synthesis of MOFs-derived SACs on N-doped carbon substrates via pyrolysis of MOFs-based metal ions or encapsulated [۳]. Currently, a wide range of MOFs as promising substrates for the preparation of SACs have been developed and some of them are briefly mentioned in Table (۱).