60 research outputs found
Ultrasound-assisted selective hydrogenation of C-5 acetylene alcohols with Lindlar catalysts
The selective hydrogenation of 2-methyl-3-butyn-2-ol (MBY) was performed in the presence of Lindlar catalyst, comparing conventional stirring with sonication at different frequencies of 40, 380 and 850 kHz. Under conventional stirring, the reaction rates were limited by intrinsic kinetics, while in the case of sonication, the reaction rates were 50–90% slower. However, the apparent reaction rates were found to be significantly frequency dependent with the highest rate observed at 40 kHz. The original and the recovered catalysts after the hydrogenation reaction were compared using bulk elemental analysis, powder X-ray diffraction and scanning and transmission electron microscopy coupled with energy-dispersive X-ray analysis. The studies showed that sonication led to the frequency-dependent fracturing of polycrystalline support particles with the highest impact caused by 40 kHz sonication, while monocrystals were undamaged. In contrast, the leaching of Pd/Pb particles did not depend on the frequency, which suggests that sonication removed only loosely-bound catalyst particles.Financial support from the European Commission for the MAPSYN project is greatly acknowledged (MAPSYN.eu No. CP-IP 309376)
Enhanced Raman Scattering as a Probe for 4-Mercaptopyridine Surface-modified Copper Oxide Nanocrystals
Effect of Surface Fluorination on the Electrochemical and Photoelectrocatalytic Properties of Nanoporous Titanium Dioxide Electrodes
Role of Interparticle Charge Transfers in Agglomerated Photocatalyst Nanoparticles: Demonstration in Aqueous Suspension of Dye-Sensitized TiO 2
Electrochemical Method for Studying the Kinetics of Electron Recombination and Transfer Reactions in Heterogeneous Photocatalysis: The Effect of Fluorination on TiO 2
Utilizing Chemical Raman Enhancement: A Route for Metal Oxide Support-Based Biodetection
Phenylethynylene-substituted poly(triphenylamine vinylene): Post-modification synthesis and (spectro)electrochemical properties
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