In 1971, Starks introduced the term “phase-transfer catalysis” to explain the critical role of tetraalkylammonium or phosphonium salts (QþX ) in the reactions between two substances located in different immiscible phases [1]. For instance, the displacement reaction of 1-chlorooctane with aqueous sodium cyanide is accelerated many thousand-fold by the addition of hexadecyltributylphosphonium bro...

ethylene was polymerized in slurry phase over a ticl4/mg(oc2h5)2 catalyst activated by al(c2h5)3. it was shown experimentally that mass transfer resistance has no effect on polymerization kinetics. after estimation ofthe active site concentration by inhibition method with carbon monoxide, the effects of polymerization temperature, monomer and cocatalyst  oncentrations and hydrogen were investig...

In the search for improved energy storage, rechargeable metal-oxygen batteries are very attractive owing to their reliance on molecular oxygen, which forms oxides on discharge that decompose reversibly on charge. Much focus has been directed at aprotic Li-O2 cells, but the aprotic Na-O2 system is of equal interest because of its better reversibility. We report here on the critical role and mech...

the use of an inorganic phase in water-in-oil (w/o) microemulsion has recently received considerable attention for preparing metal oxide nanoparticles. this is a technique, which allows preparation of ultrafine metal oxide nanoparticles within the size range 40 to 80 nm. preparation of nano chromium (iii) oxide studied investigated in the inverse microemulsion system. therefore the nucleation o...

A novel variant of an iridium-based organometallic catalyst was synthesized and used to enhance the NMR signals of pyridine in a heterogeneous phase by immobilization on polymer microbead solid supports. Upon administration of parahydrogen (pH2) gas to a methanol mixture containing the HET-SABRE catalyst particles and the pyridine, up to fivefold enhancements were observed in the (1)H NMR spect...

Semiconductor photocatalytic process has been studied extensively in recent years due to its intriguing advantages in environmental remediation. In this study, a two-phase swirl-flow monolithic-type reactor is used to study the kinetics of photocatalytic degradation of benzoic acid in immobilized systems. Transport contributions into the observed degradation rates were determined when catalyst ...

Currently, ingenious new analytical and process experimental techniques which are environmentally benign techniques, viz., ultrasound irradiation, have become immensely popular in promoting various reactions. In this work, a novel soluble multi-site phase transfer catalyst (PTC) viz., 1,4-bis-(propylmethyleneammounium chloride)benzene (BPMACB) was synthesized and its catalytic efficiency was as...

monometallic and bimetallic ni and co catalytic nanoparticles supported on titanium dioxide (rutile phase) substrate were prepared by wet impregnation method. these nanoparicles were used as catalysts for synthesis of multiwalled carbon nanotubes (mwcnts) from acetylene decomposition at 700°c by the catalytic chemical vapor deposition (ccvd) technique. the nanomaterials (catalyst and cnts) were...

Three – Phase Sparged Reactors are widely used in Chemical, Bio-Chemical and Petrochemical Industrial processes. The advantages of these reactors include high mass and heat transfer rates,isothermal conditions and on-line catalyst addition and withdrawl. The high heat transfer rates of Three-Phase Sparged Reactors are particularly attractive for highly exothermic reactions where substantial red...

The hetght of an ovemll transfer unat has been evaluated m a gas-solid packed column at tnckle flow by measunng column performance during steady state adsorption expertments. Results have been anterpreted wtth an extmctton model mass transfer and axial dispersaon ua both phases Usmg Bodenstem numbers for the gas and solid phases from a previous investagation the hetght of a true transfer untt h...