A novel imido-modified SiO2-supported Ti/Mg Ziegler-Natta catalyst for ethylene and ethylene/1-hexene polymerization is investigated. The catalyst is prepared by modification of (SiO2/MgO/MgCl2)TiClx Ziegler-Natta catalysts via supporting vanadium species followed by reaction with p-tolyl isocyanate as imido agents, to get the merits from both the SiO2-supported imido vanadium catalyst and the ...

Organometallic Ir precatalysts have been found to yield homogeneous Ir-based water-oxidation catalysts (WOCs) with very high activity. The Cp*Ir catalyst series can operate under a variety of regimes: it can either act as a homogeneous or a heterogeneous catalyst; it can be driven by chemical, photochemical, or electrochemical methods; and the molecular catalyst can either act in solution or su...

Molecular catalysts are known for their high activity and tunability, but their solubility and limited stability often restrict their use in practical applications. Here we describe how a molecular iridium catalyst for water oxidation directly and robustly binds to oxide surfaces without the need for any external stimulus or additional linking groups. On conductive electrode surfaces, this hete...

Summarization of electronic discussion fora is a unique challenge; techniques that work startlingly well on monolithic documents tend to fare poorly in this informal setting. Additionally, conventional techniques ignore much of the structures that have the potential to serve as valuable features in the summarization task. We present several novel examples of such features, including the catalys...

A series of dinitrogen-bridged dimolybdenum-dinitrogen complexes bearing metallocene-substituted PNP-pincer ligands is synthesized by the reduction of the corresponding monomeric molybdenum-trichloride complexes under 1 atm of molecular dinitrogen. Introduction of ferrocene as a redox-active moiety to the pyridine ring of the PNP-pincer ligand increases the catalytic activity for the formation ...

a new model based on a combination of the polymeric multigrain and multilayer models has been developed to predict the polymerization rate, particle growth, morphology, effective parameters on broadening of the molecular weight distribution, number and weight average of the molecular weight, isotacticity index and bulk density of polymer. mathematical correlations and the kinetics used in this ...

Hydrogen is considered as a unique choice for future world’s resources. The important parameter in the process of hydrogen production is the value of reduction potential for the used catalyst, in direct contact with consumed energy in process. The application of computational methods to design and modify molecular catalysts is highly regarded. This study sought to explore Density Functional...

In recent year, biocompatible, biodegradable materials (linear polylactic acid-based urethanes) in the solid and/or liquid form have attracted tremendous attention in biomedical application particularly in stent coating. Low molecular weight poly (lactic acid) s (PLA), having narrow molecular weight distribution was by dehydropolycondensation method using tetraphenyltin as a catalyst. Hydroxyl ...

Molecular weight enlargement (MWE) is an attractive method for homogeneous catalyst recycling. Applications of MWE in combination with either catalyst precipitation or nanofiltration have demonstrated their great potential as a method for process intensification in homogeneous catalysis. Selected, recent advances in MWE in combination with catalyst recovery are discussed, together with their im...

We study the restructuring of solid nickel catalyst nanoparticles during carbon nanotube growth by environmental transmission electron microscopy and multiscale modeling. Our molecular dynamics/continuum transport calculations of surface-diffusion-mediated restructuring are in quantitative agreement with the experimentally observed catalyst shape evolutions. The restructuring time scale is dete...