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Nanomaterials are more effective than conventional catalysts for two reasons. First, their extremely small size (typically 10–80 nm) yields a tremendous surface area-to-volume ratio. Also, when materials are fabricated on the nanoscale, they achieve properties not found within their macroscopic counterparts. Both of these reasons account for the versatility and effectiveness of nanocatalyst.

Since the end of the 1990s, with the development of Nanoscience, nanocatalysis has emerged as a domain at the interface between homogeneous and heterogeneous catalysis, which offers unique solutions to answer the demanding conditions for catalyst improvement [2, 3]. The main focus is to develop well-defined catalysts, which may include both metal nanoparticles and a nanomaterial as support. These nanocatalysts should be able to display the ensuing benefits of both homogeneous and heterogeneous catalysts, namely high efficiency and selectivity, stability and easy recovery or recycling. Specific reactivity can be anticipated due to the nano dimension that can afford specific properties which cannot be achieved with regular, non-nano materials. Nano-catalytic system allows rapid, selective chemical transformations with excellent product yield coupled with the ease of catalyst separation and recovery. Because of its nano size (high surface area) the contact between reactants and catalyst increases dramatically. Insolubility in the reaction solvent makes the catalyst heterogeneous and hence can be separated out easily from the reaction mixture.

Nanoparticles are recognized as the most important industrial catalyst and have wider application ranging from chemical manufacturing to energy conversion and storage. Its variable and particle-specific catalytic activity is due to their heterogeneity and their individual differences in size and shape. The fine tuning of nanocatalyst, in terms of composition (bimetallic, core-shell type or use of supports), shape and size has accomplished greater selectivity. Thus, the question here is how the physical properties of nanoparticles affect their catalytic properties, and how fabrication parameters can in turn affect those physical properties. By a better understanding of these, a scientist can design nanocatalysts, which are highly active, highly selective, and highly resilient. All these advantages will enable industrial chemical reactions to become more resource efficient, consume less energy, and produce less waste, which also helps to counter the environmental impact caused by our reliance on chemical processes.