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...

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...

the mono-metallic and bi-metallic catalysts have been prepared by impregnating with solutions containing a compound of h2ptcl6,wo3 and 1ml hcl (0.1 mol). it should be noted that the catalysts’ activity and selectivity have been determined under these conditions : 450-5000c ,and 15-25atm by h2. for converting n-heptane , the molar ratio h2/c7h16 is 5 , and lhsv is 1.5ml/h. it has been proved tha...

Magnetically recyclable catalysts with magnetic nanoparticles (MNPs) are becoming a major trend towards sustainable catalysts. In this area, recyclable supported ruthenium complexes and ruthenium nanoparticles occupy a key place and present great advantages compared to classic catalysts. In this micro-review, attention is focused on the fabrication of MNP-supported ruthenium catalysts and their...