Since the introduction in I974 of catalytic converters for automotive emission control i n the United States significant advances have been made in the design of durable monolith supported catalysts for the control of carbon monoxide, unburnt hydrocarbon and nitrogen oxide emissions. However, high temperature durability, has been a significant problem, particularly of three-way catalysts. Johns...

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...

The catalyst formation in the system Ni(acac),, C&I,, (iBu)sAl was investigated by means of infrared spectroscopy. It was found that the Al(acac)s and (iBu)&l(acac) formed are both by-products of catalyst formation without a catalytic activity. Ni(acac)z loses its acac groups forming the unstable (iBu)sNi compound; without CsH, being present, this compound disproportionates to Ni metal and isob...

We report a process for converting fructose, at a high concentration (15 weight %), to 2,5-furandicarboxylic acid (FDCA), a monomer used in the production of polyethylene furanoate, a renewable plastic. In our process, fructose is dehydrated to hydroxymethylfurfural (HMF) at high yields (70%) using a γ-valerolactone (GVL)/H2O solvent system. HMF is subsequently oxidized to FDCA over a Pt/C cata...

ZnO nanowire nucleation mechanism and initial stages of nanowire growth using the carbothermal reduction technique are studied confirming the involvement of the catalyst at the tip in the growth process. Role of the Au catalyst is further confirmed when the tapering observed in the nanowires can be explained by the change in the shape of the catalyst causing a variation of the contact area at t...

This review describes our recent efforts in the development of acid-base organocatalysts, (S)-3-(N-isopropyl-N-3-pyridinylaminomethyl) BINOL (6a) and (S)-3-[2-(diphenylphosphino)phenyl] BINOL (13a), with dual activation mechanism for the aza-Morita-Baylis-Hillman (aza-MBH) reaction. In these catalysts, chiral Brønsted acid units are connected with a Lewis base unit via a spacer. The acid-base m...

Microalgae have been receiving worldwide attention as promising feedstock for production of carbon neutral biodiesel. As an alternative fuel, biodiesel is very imperative for the sustainable development of mankind. Biodiesel production process is generally carried out through upstream and downstream processing to generate cellular biomass, extracted oil and finally transesterification reaction....

A water-soluble PdCl₂(NH₃)₂/cationic 2,2'-bipyridyl system was found to be a highly efficient catalyst for Stille coupling of aryl iodides and bromides with organostannanes. The coupling reaction was conducted at 110 °C in water, under aerobic conditions, in the presence of NaHCO₃ as a base to afford corresponding Stille coupling products in good to high yields. When aryltributylstannanes were ...

The lack of stability is a challenge for most heterogeneous catalysts. During operations, the agglomeration of particles may block the active sites of the catalyst, which is believed to contribute to its instability. Recently, titanium oxide (TiO2) was introduced as an alternative support material for heterogeneous catalyst due to the effect of its high surface area stabilizing the catalysts in...

The cross-coupling reaction between phenylboronic acid and various types of aryl halides (Suzuki reaction) was carried out using a catalytic amount of a new palladium catalyst (1-benzyl-3-(1-benzyl-1-methylpyrrolidin-1-ium-2-yl) pyridin-1-ium palladium chloride [DBNT][PdCl4]) in poly (ethylene glycol) (PEG-200) in the presence of KOH as the base. This new catalyst was synthesized and...