Nano-catalysis is a rapidly evolving field that explores the use of nanomaterials as catalysts to enhance the rate, selectivity, and efficiency of chemical reactions. Due to their high surface area-to-volume ratio and tunable surface properties, nanocatalysts offer superior activity and stability compared to conventional bulk catalysts. These materials, including metal nanoparticles, nanocomposites, and supported nanostructures, play a pivotal role in applications such as energy conversion, environmental remediation, green chemistry, and industrial synthesis. By manipulating size, shape, and composition at the nanoscale, researchers can tailor catalytic behavior for specific reactions, including photocatalysis, electrocatalysis, and heterogeneous catalysis. Nano-catalysis not only improves process efficiency and sustainability but also paves the way for innovative solutions to address global energy and environmental challenges.