Preparation of Ultrafine Palladium Particles in Reverse Micelles and Application for Hydrogenation Catalysts.

Recent Advances in the Liquid‐Phase Synthesis of Metal Nanostructures with Controlled Shape and Size for Catalysis

“…CTAB-stabilized Au nanoparticles were mixed with activated carbon and used directly for liquid-phase ethylene glycol oxidation, however, the surfactant decreased the catalyst activity (61). Indeed, if a major part of a stabilizer is not removed from the particle surface, it can lead even to the complete loss of activity, e.g., Pd nanoparticles synthesized in microemulsion by AOT and deposited onto metal oxides showed zero activity in allyl alcohol hydrogenation, but the calcined catalysts showed high conversions (60).…”

“…Mixing of the modified particles and support resulted in stable particles which did not leach out during liquid-phase allyl alcohol hydrogenation. However, thiol groups poisoned some active sites leading to the decreased activity (60). The colloidal nanoparticles stabilized by PVP can be also captured on metal oxide supported modified with 3-mercaptopropyltrimethoxysilane: the nanoparticles were precipitated in acetone by centrifugation and redispersed in dichloromethane containing MPS to exchange the maximum of PVP with MPS ligand, followed by the support addition.…”

Synthesis of monodispersed palladium nanoparticles to study structure sensitivity of solvent-free selective hydrogenation of 2-methyl-3-butyn-2-ol

“…ME-derived nanoparticles are widely used in catalytic reactions, mainly as a nanoparticle-containing MEs per se or deposited onto supports. The use of ME itself [18][19][20][21][22][23][24][25] implies the addition of extra components to the catalytic reaction mixture (hydrocarbon, water, surfactant, excess of a metal re-ducing agent). This leads to an increase of the reaction volume, and a catalytic reaction may be affected through "medium" and "solubilization" effects [26,27].…”

“…Nanoparticles also may be deposited onto solid support by mixing the ME with a support. This step is usually followed by calcination [12,16,17,21,[31][32][33][34][35][36][37][38][39][40][41]. However, these heterogeneous catalysts can be hardly applied for size effect studies because of specific particlesupport interactions [21] and the sintering of the particles at high temperatures during the calcination step.…”

Palladium nanoparticles stabilized in block-copolymer micelles for highly selective 2-butyne-1,4-diol partial hydrogenation

“…Studies have found an inhibiting effect of surfactants on particles' catalytic activity [6,18]. The surfactant removal after the micelles immobilization onto solid supports significantly increases the catalytic activity, but the main advantage of micellar catalysis, i.e., the improvement of the catalyst performance due to the specific medium [13] is lost.…”