There is a widespread interest in developing methods to recover homogeneous catalysts, particularly chiral catalysts, from a reaction mixture. The impetus to recover and reuse homogeneous catalysts stems not only from an economic standpoint but also from the need to eliminate contamination of the transition metal catalyst in the product and in the waste streams. The challenge is to recover the ...

Chromium-vanadium (Cr-V) bimetallic catalysts are prepared by the introduction of vanadium into the Phillips catalyst which is one of the most significant industrial ethylene polymerization catalysts for tuning the Phillips catalyst performances and improving polyethylene properties. In the present work, titanium species were introduced into the fluorine-modified chromium-vanadium bimetallic ca...

mg(oet)2 with spherical morphology is one of the most important precursors for the preparation of industrialziegler-natta catalysts. in the present article, morphology evolution of mg(oet)2 particles is studied in the courseof the synthesis. the morphology of mg(oet)2 particles is observed throughout the process by sem. the resultsshow that mg(oet)2 particles are formed through i) seed generati...

BACKGROUND Transesterification catalyzed by solid base catalyst is a brilliant technology for the noble process featuring the fast reaction under mild reacting condition in biodiesel production. Heterogeneous base catalysts are generally more reactive than solid acid catalysts which require extreme operating condition for high conversion and biodiesel yield. In the present study, synthesis of b...

in this work, tio2 /sio2 (pure anatase), and tio2 /sio2 (anatase/rutile) nano-photocatalysts are prepared by using sol-gel method and control of acidity. the particles size is calculated using scheerer, s equation and is estimated to be around 7-15 nm. in order to improve the photocatalytic activity of tio2 /sio2 ,1% (wt) platinum particles are loaded on both catalysts using photoreductive meth...

lamno3 and lamno3/zsm-5 nano catalysts were synthesized by pechini method and their physical-chemical properties were characterized using xrd, ftir, sem-edx, uv-vis drs, bet surface area and tpr. the correlation between characteristic properties and activity of catalysts were investigated. the catalytic performance of the catalysts was evaluated in combustion of 2-propanol and compared with 1% ...

Noble metal catalysts have been widely used in many applications because of their high activity and selectivity. However, a controllable preparation of noble metal catalysts still remains as a significant challenge. To overcome this challenge, peptide templates can play a critical role in the controllable syntheses of catalysts owing to their flexible binding with specific metallic surfaces and...

A new family of Tetraazamacrocyclic Ru(II) complexes [RuCl2(L)] (where L = N4 donor macrocyclic ligands) have been synthesized by the reactions of [RuCl2(DMSO)4] with some of macrocyclic Schiff base ligands containing N4 donor groups. The complexes were characterized by elemental analysis, IR, H, C NMR, mass, electronic, molar conductance and magnetic susceptibility measurements. An octahedral ...

We developed neutral iridium catalysts with chiral spiro phosphine-carboxy ligands (SpiroCAP) for asymmetric hydrogenation of unsaturated carboxylic acids. Different from the cationic Crabtree-type catalysts, the iridium catalysts with chiral spiro phosphine-carboxy ligands are neutral and do not require the use of a tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BArF-) counterion, which is ne...

A novel, solvent-deficient precipitation (SDP) method for catalyst preparation in general and for preparation of iron FT catalysts in particular is reported. Eight catalysts using a 23 factorial design of experiments to identify the key preparation variables were prepared. The catalysts were characterized by electron microprobe, N2 adsorption, TEM, XRD, and ICP. Results show that the morphology...