Journal of Research in Applied Chemistry

Authors: Ashok Kulkarni¹, Pooja Joshi²

Abstract: Single-atom catalysts (SACs) have emerged as a new frontier in heterogeneous catalysis and are attracting strong attention for clean energy applications. In SACs, isolated metal atoms are anchored on suitable supports, combining the advantages of homogeneous and heterogeneous catalysis. The unique electronic structure, maximum atom utilization, and tunable coordination environment make SACs promising for energy-related reactions such as hydrogen evolution, oxygen reduction, oxygen evolution, CO₂ reduction, and nitrogen fixation. This review discusses the fundamental concepts of single-atom catalysis, synthesis strategies, characterization techniques, and structure–performance relationships. Recent advances in SACs for clean energy conversion and storage are critically analyzed, highlighting both achievements and limitations. Challenges related to stability, scalability, and realistic operating conditions are also discussed. Finally, future perspectives on the rational design of SACs for sustainable energy technologies are provided. Overall, single-atom catalysis offers a viable pathway toward high efficiency and low-cost catalysts for next-generation clean energy systems.

Keywords: Single-atom catalysts, clean energy, electrocatalysis, hydrogen evolution, CO₂ reduction, sustainable catalysis