A combination of the advantages of homogeneous and heterogeneous catalysis could enable the development of sustainable catalysts with novel reactivity and selectivity. Although heterogeneous catalysts are often recycled more easily than their homogeneous counterparts, they can be difficult to apply in traditional organic reactions and modification of their properties towards a desired reactivit...

platinum extraction from different secondary sources has been experimentally tested by many researchers. in this article, dissolution of platinum in aqua-regia solution from two types of spent catalysts (reforming and nitric acid production) was kinetically studied. a variety of kinetic models for heterogeneous solid-liquid reactions, including homogeneous diffusion model, shrinking core model,...

In this study, Mn (III) salen complex was synthesized and immobilized onto the graphene oxide, which is modified by 3-chloropropyltrimethoxy silane. Heterogeneous catalyst was characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, fourier transform infrared spectra, nitrogen adsorption−desorption isotherm and atomic absorption spectroscopy. The catalyt...

The combination of scCO2 with a non-volatile liquid such as ionic liquids, water, or poly(ethylene glycol) creates a biphasic mixture suitable for homogeneous catalysis with facile catalyst/product separation and catalyst recycling. Continuous-flow processes are also possible. Dissolution of the CO2 into the nonvolatile liquid during the reaction can have desirable or undesirable effects on the...

In this paper, we reported a new simple and effective method, osmotic membrane-assisted self-assembly, for fabricating massive interconnected macroporous silica monolith as catalyst supports. Using the method, we can prepare massive interconnected macroporous silica monolith with homogeneous structures beyond millimeter scale one time. Typically, silica/polystyrene and polystyrene/poly 4-vinyl ...

Some of the most efficient homogeneous catalysts for the lowtemperature, selective oxidation of methane to functionalized products employ a mechanism involving C H activation with an electrophilic substitution mechanism. Several such systems have been reported based on the cations Hg, Pd, and Pt. These catalyst systems typically operate by two general steps that involve: A) C H activation by co...

Studies on the synthesis of esters of natural origin fatty acids (oleic acid) and a branched synthetic isostearic acid derived from oleic acid with commercially available selected higher polyols in the presence of homogeneous metallic catalysts have been carried out. The effects of the synthesis temperature, molar ratio and the catalysts amount have also been studied. It was shown that higher f...

This article describes a new strategy for the recycling of a homogeneous hydroformylation catalyst, by selective adsorption of the catalyst to tailor-made supports after a batchwise reaction. The separation of the catalyst from the product mixture is based on selective non-covalent supramolecular interactions between a ligand and the support. Changing the solvent releases the active catalyst ba...

We report a mechanistically based study of bifunctional catalyst systems in which chiral nucleophiles work in conjunction with Lewis acids to produce beta-lactams in high chemical yield, diastereoselectivity, and enantioselectivity. Chiral cinchona alkaloid derivatives work best when paired with Lewis acids based on Al(III), Zn(II), Sc(III), and, most notably, In(III). Homogeneous bifunctional ...