Metallic Nanocatalysis: An Accelerating Seamless Integration with Nanotechnology

Abstract

Rapidly growing research interests surround heterogeneous nanocatalysis, in which metal nanoparticles (NPs) play a pivotal role as structure-sensitive active centers. With advances in nanotechnology, the morphology of metal NPs can be precisely controlled, which can provide well-defined models of nanocatalysts for understanding and optimizing the structure-reactivity correlations and the catalytic mechanisms. Benefiting from this, further credible evidence can be acquired on well-defined nanocatalysts rather than common multiphase systems, which is of great significance for the design and practical application of active metal nanocatalysts. Numerous studies demonstrate that enhanced structure-sensitive catalytic activity and selectivity are dependent not only on an increased surface-to-volume ratio and special surface atom arrangements, but also on tailored metal-metal and metal-organic-ligand interfaces, which is ascribed to the size, shape, composition, and ligand effects. Size-reactivity relationships and underlying size-dependent metal-oxide interactions are observed in many reactions. For bimetallic nanocatalysts, the composition and nanostructure play critical roles in regulating reactivities. Crystal facets favor individual catalytic selectivity and rates via distinct reaction pathways occurring on diverse atomic arrangements, both to low-index and high-index facets. High-index facets exhibit superior reactivities owing to their high-energy active sites, which facilitate rapid bond-breaking and new bond generation. Additionally, organic ligands may enhance the catalytic activity and selectivity of metal nanocatalysts via changing the adsorption energies of reactants and/or reaction energy barriers. Furthermore, atomically dispersed metals, especially single-atom metallic catalysts, have emerged recently, which can achieve better specific catalytic activity compared to conventional nanostructured metallic catalysts due to the low-coordination environment, stronger interaction with supports, and maximum service efficiency. Here, recent progress in shaped metallic nanocatalysts is examined and several parameters are discussed, as well as finally highlighting single-atom metallic catalysts and some perspectives on nanocatalysis. The integration of nanotechnology and nanocatalysis has been shaping up and, no doubt, the combination of sensitive characterization techniques and quantum calculations will play more important roles in such processes.

Alloying Behavior of Self‐Assembled Noble Metal Nanoparticles

“…They open up new promising application fields in energy conversion and storage, electronics, sensing, and heterogeneous catalysis . Moreover, they exhibit synergistic electronic and geometric effects that strongly differ from the single contributions of each element . It is essential to know the accurate elemental distributions and crystallinities within multimetallic nanostructures, as these parameters strongly influence their chemical, catalytic, and physical properties.…”

Influence of the metal loading on the electrocatalytic activity of carbon-supported (100) Pt nanoparticles

“…In the quest for better electrocatalysts, the use of shapecontrolled metal nanoparticles has had an important impact [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Thus, these types of nanoparticles have allowed a better understanding of the surface structure-electrochemical reactivity correlations on the nanoscale.…”

Hydrogenation of allyl alcohols catalyzed by aqueous palladium and platinum nanoparticles

“…16 Hydrogenations are normally performed using hydrogen gas and heterogeneous metal catalysts, such as Raney Nickel or Palladium, Rhodium or Platinum metals. 27,28 In particular, some Palladium and Platinum NPs are reported to be active catalysts in the hydrogenation of unsaturated hydrocarbons or allyl alcohols. [21][22][23][24][25][26] Metal nanoparticles (NPs) are becoming increasingly attractive for industrial catalysis, thanks to their high surface-to-volume ratio, easy preparation and tunable dimensions.…”