Mesoporous spherical silica encapsulating Pd nanoparticles prepared by CO 2 -induced mircoemulsion and catalytic application in Suzuki coupling reaction

Green Synthesis of Nanosilica from Coal Fly Ash and Its Stabilizing Effect on CaO Sorbents for CO2 Capture

“…This significant result may be owing to the effect of CO 2 , which also played a role as template. Li et al also reported the templated effect of CO 2 -in-water microemulsion for synthesis of uniform spherical mesoporous silica . The excessive rates of CO 2 (η CO2 ; Table S2, calculated based on eqs S1 and S2) were 5.88, 2.94, 1.47, 0.98, and 0.74 for C Na2SiO3 of 10, 20, 40, 60, and 80 g L –1 , respectively.…”

“…Li et al also reported the templated effect of CO 2 -inwater microemulsion for synthesis of uniform spherical mesoporous silica. 48 The excessive rates of CO 2 (η CO2 ; Table S2, calculated based on eqs S1 and S2) were 5.88, 2.94, 1.47, 0.98, and 0.74 for C Na2SiO3 of 10, 20, 40, 60, and 80 g L −1 , respectively. When C Na2SiO3 increased, the pore size of nano-SiO 2 -4% also enlarged with a wider distribution centered at 4.3−76.3 nm.…”

Colloidal Silica Particle Synthesis and Future Industrial Manufacturing Pathways: A Review

“…147 A microemulsion was then injected into the supercritical CO 2 at 35 °C, whereupon the solvent was extracted and the exposed surface of the aqueous droplets reacted with the CO 2 producing nanosized silica within the size range of 20−800 nm depending on the reactant concentrations. 147 This process has consequently been used in the development of silica coating procedures 148,149 and silica−polymer composite synthesis. 150 More recent work has focused on developing pre-existing m i c r o e m u l s i o n s y n t h e s i s m e t h o d s f o r s p e c i fi c uses.…”

Organometallic interactions between metal nanoparticles and carbon-based molecules: A surface reactivity rationale

“…45 Analogous synergistic effects have also been described by Ye and co-workers for highly active core-shell microspheres, bearing a magnetic Fe3O4 core, a layer of PdNPs and an outer shell of mesoporous CeO2. The preparation of highly active catalytic materials with enhanced reusability properties has also been enabled by the immobilization of PdNPs on solids supports such as silicates (mesoporous SiO2, 113,114 mercaptopropyltrimethoxysilane-SiO2, 115 PEG-SiO2, 116 silicalite-1, 117 montmorillonite 47 ), ZnAl2O4 spinel, 118 ferrite, 119 magnetite, 120,121 chalcogels, 122 covalent organic frameworks, [123][124][125] metal organic frameworks (Eu-MOF, 126 MCM-41, 127 MOF-5, 128,129 MIL-101, 130 Cu-MOF, 131 ) Carbon-based materials (graphene, 111 graphene oxide, [132][133][134] graphene acid, 53 Carbon nanotubes 135 ), polymeric matrixes [dendrimers, 108 poly(amido-amine) (G4-PAMAM), 106 2-aminobenzaldehyde modified chitosan nanofibers, 136 DIANION, 137 mesoporous polyaminophenols, 138,139 poly(ethylene glycol)-co-poly(Nisopropylacrylamide), 140 nylon rope 141 ], or composite materials of mixtures thereof. [142][143][144][145][146][147] Literature reports on surface-like Suzuki-Miyaura cross-couplings under aerobic conditions address the challenge of precluding boronic acid homo-coupling, a competing side reaction occurring in the presence of O2 via the formation of palladium(II) peroxo species 148 that can easily undergo two successive transmetallations with boronic acid substrates as aryl halide oxidative addition to Pd(0) is the rate determining step under classical molecular regimes.…”