نتایج جستجو برای: phase transfer catalyst
تعداد نتایج: 909786 فیلتر نتایج به سال:
Abstract A new multi-site phase-transfer catalyst (MPTC), viz., N,N’-dioctyl-4,4’-bipyridium dibromide containing bi-site was prepared and proved by FT-IR, 1H NMR, 13C NMR, mass and elemental analysis. The enhancement of C-N+ peak intensity at 1179 cm−1 noticed in FT-IR, the agreement of m/z values, viz., 542.43 bi-site respectively with their theoretical values and the percentage of C, H, N e...
Methanol synthesis is one of the landmarks of heterogeneous catalysis due to the great industrial significance of methanol as a clean liquid fuel and as a raw material for industry. Understanding in atomistic detail the properties of the underlying metal/oxide catalyst materials as a function of temperature and composition of the reactive gas phase is of utmost importance in order to eventually...
Danckwert's method was used to determine the specific interfacial area, a, and the individual mass transfer coefficient, k(L), during absorption of CO(2) in a bubble column with an anionic surfactant in the carbonate-bicarbonate buffer solution and NaAsO(2) as catalyst, the presence of which decreases the specific interfacial area and the individual mass transfer coefficient. The specific inter...
Polymer-supported chiral 1,2-diamine derivatives have been prepared. The polymers containing free 1,2-diamine moiety were applied to enantioselective hydrogenation catalyst by combination with RuCl2-BINAP complex. Asymmetric hydrogenation of aromatic ketones was performed by means of the polymeric catalyst derived from these polymers to give the chiral secondary alcohols with high ee in quantit...
Sodium borohydride (NaBH4) hydrogen storage systems offer many advantages for hydrogen storage applications. The physical processes inside a NaBH4 packed bed reactor involve multi-component and multi-phase flow and multi-mode heat and mass transfer. These processes are also coupled with reaction kinetics. To guide reactor design and optimization, a reactor model involving all of these processes...
A covalently linked organic dye-cobaloxime catalyst system based on mesoporous NiO is synthesized by a facile click reaction for mechanistic studies and application in a dye-sensitized solar fuel device. The system is systematically investigated by photoelectrochemical measurements, density functional theory, time-resolved fluorescence, transient absorption spectroscopy, and photoelectron spect...
In the area of catalytic asymmetric epoxidation, the highly enantioselective transformation of cyclic enones and quinones is an extremely challenging target. With the aim to develop new and highly effective phase-transfer catalysts for this purpose, we conducted a systematic structural variation of PTCs based on quinine and quinidine. In the total of 15 new quaternary ammonium PTCs, modificatio...
The selective hydrogenation of chalcone to dihydrochalcone under atmospheric hydrogen pressure is investigated using a thermoregulated phase-transfer ruthenium nanocatalyst, representing the first nanocatalyst used for this reaction. Under optimal conditions, conversion into and selectivity are 98% >99%, respectively. catalyst can be easily separated from product recycled three times without...
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