The aim of this study was to examine the effect of catalyst doping on the performance of MgCl2. EtOH/TiCl4 catalyst system. In this regard, a series of undoped as well as FeCl3-doped catalysts was prepared and employed in 1-hexene polymerization. A modified catalyst containing 10 wt. % of FeCl3 dopant demonstrated the highest activity, with 32% activity increase compared to unmodified one, amon...

Nature invented a catalyst about 3Gyr ago, which splits water with high efficiency into molecular oxygen and hydrogen equivalents (protons and electrons). This reaction is energetically driven by sunlight and the active centre contains relatively cheap and abundant metals: manganese and calcium. This biological system therefore forms the paradigm for all man-made attempts for direct solar fuel ...

Biphasic catalytic olefin epoxidation systems consisting of oxodiperoxomolybdenum catalysts in 1-n-alkyl-3-methylimidazolium hexafluorophosphate ionic liquid (IL) media with aqueous hydrogen peroxide oxidant were optimised by tuning the molecular structure of the IL and employing N-heterocyclic donor base additives to inhibit hydrolysis and enhance the activity of the catalyst. The latter study...

Ruthenium and molybdenum catalysts are widely used in synthesis of both small molecules and macromolecules. While major developments have led to new increasingly active catalysts that have high functional group compatibility and stereoselectivity, catalyst/product separation, catalyst recycling, and/or catalyst residue/product separation remain an issue in some applications of these catalysts. ...

Ab initio calculations predict that pyridine (Py) can act as a photo-catalyst to split water by the absorption of a UV photon following the reaction Py-H2O + hν → PyH˙ + OH˙. To test this prediction, we performed two types of experiments: in the first, we characterize the electronic spectroscopy of the PyH˙ radical in the gas phase. In the second, we evidence the reaction through the UV excitat...

We report the observation of phase coherent transport in catalyst-free InAs and InAs1−xSbx nanowires grown by molecular beam epitaxy on silicon (111) substrates. We investigate three different methods to gain information on the phase coherence length of the nanowires: first through the study of universal conductance fluctuations as a function of both magnetic field and gate voltage and then thr...

We demonstrate photocatalytic hydrogen evolution using COF photosensitizers with molecular proton reduction catalysts for the first time. With azine-linked N2-COF photosensitizer, chloro(pyridine)cobaloxime co-catalyst, and TEOA donor, H2 evolution rate of 782 μmol h-1 g-1 and TON of 54.4 has been obtained in a water/acetonitrile mixture. PXRD, solid-state spectroscopy, EM analysis, and quantum...

The theoretically predicted volcano plot for hydrogen production shows the best catalyst as the one that ensures that the hydrogen binding step is thermodynamically neutral. However, the experimental realization of this concept has suffered from the inherent surface heterogeneity of solid catalysts. It is even more challenging for molecular catalysts because of their complex chemical environmen...

The selective oxidation of lactose by molecular oxygen has been studied in a batch reactor containing an aqueous slurry of 0.5 kmol m-1 reactant and 1.0 kg m-3 catalyst. The in situ Bi promotion of a commercial Pd-C catalyst resulted in 100% selectivity to sodium lactobionate up to conversions of 95% in the pH range 7-10 and at temperatures up to 333 K. Performing the reaction under such condit...

A commercially available Hoveyda-Grubbs type catalyst (RC303 Zhannan Pharma) was immobilized on mesoporous molecular sieves MCM-41 and on SBA-15 by direct interaction with the sieve wall surface. The immobilized catalysts exhibited high activity and nearly 100% selectivity in several types of alkene metathesis reactions. Ru leaching was found to depend on the substrate and solvent used (the low...