Nanoscience has significantly impacted the field of heterogeneous catalysis by enabling a molecular-level understanding of how nanoparticle properties influence catalytic performance. Catalysts, which are essential for many industrial processes, often consist of nanoparticles dispersed on high-surface-area supports. Advances in characterization techniques, such as transmission electron microscopy (TEM), scanning tunneling microscopy (STM), and synchrotron radiation, have allowed researchers to study the size, shape, and composition of nanoparticles in detail. These insights, combined with novel synthesis methods, have led to the development of more efficient and selective catalysts. The performance of catalysts is highly dependent on the size, shape, and surface structure of the nanoparticles. For example, gold nanoparticles supported on titania are more active for the oxidation of CO when they are in the size range of 2-3 nm. Similarly, vanadia nanoparticles supported on different oxides show increased activity for the oxidative dehydrogenation of alkanes to olefins as their size increases. The electronic properties of the nanoparticles, influenced by their size and composition, play a critical role in determining their catalytic activity and selectivity. Local composition and structure of catalyst nanoparticles also affect their performance. For instance, the addition of a small amount of cobalt to molybdenum disulfide layers on alumina significantly enhances the desulfurization activity of the catalyst. Understanding these factors is crucial for designing catalysts that can operate efficiently under reaction conditions. Advances in synthesis methods have enabled the creation of catalysts with precise control over size, shape, and composition. This has led to the development of single-site catalysts, where all active sites are identical, and well-defined porous supports that can be used for catalytic applications. These developments are contributing to the goal of catalysis by design, where catalysts can be tailored to specific reactions and conditions. Overall, nanoscience is playing a vital role in advancing the field of heterogeneous catalysis, leading to more efficient and sustainable chemical processes.Nanoscience has significantly impacted the field of heterogeneous catalysis by enabling a molecular-level understanding of how nanoparticle properties influence catalytic performance. Catalysts, which are essential for many industrial processes, often consist of nanoparticles dispersed on high-surface-area supports. Advances in characterization techniques, such as transmission electron microscopy (TEM), scanning tunneling microscopy (STM), and synchrotron radiation, have allowed researchers to study the size, shape, and composition of nanoparticles in detail. These insights, combined with novel synthesis methods, have led to the development of more efficient and selective catalysts. The performance of catalysts is highly dependent on the size, shape, and surface structure of the nanoparticles. For example, gold nanoparticles supported on titania are more active for the oxidation of CO when they are in the size range of 2-3 nm. Similarly, vanadia nanoparticles supported on different oxides show increased activity for the oxidative dehydrogenation of alkanes to olefins as their size increases. The electronic properties of the nanoparticles, influenced by their size and composition, play a critical role in determining their catalytic activity and selectivity. Local composition and structure of catalyst nanoparticles also affect their performance. For instance, the addition of a small amount of cobalt to molybdenum disulfide layers on alumina significantly enhances the desulfurization activity of the catalyst. Understanding these factors is crucial for designing catalysts that can operate efficiently under reaction conditions. Advances in synthesis methods have enabled the creation of catalysts with precise control over size, shape, and composition. This has led to the development of single-site catalysts, where all active sites are identical, and well-defined porous supports that can be used for catalytic applications. These developments are contributing to the goal of catalysis by design, where catalysts can be tailored to specific reactions and conditions. Overall, nanoscience is playing a vital role in advancing the field of heterogeneous catalysis, leading to more efficient and sustainable chemical processes.