Olefin metathesis is a prevailing method for the construction of organic molecules. Recent advancements in olefin metathesis have focused on stereoselective transformations. Ruthenium olefin metathesis catalysts have had a particularly pronounced impact in the area of stereoselective olefin metathesis. The development of three categories of Z-selective olefin metathesis catalysts has made Z-ole...

Ni-, Co-, and Ptpromoted MoVNbOx mixed metal oxide catalysts were prepared by impregnation method. The physicochemical properties of the catalysts showed that the BET surface area of the promoted catalysts was lower when compared to the unpromoted catalysts due to the filling of open pores by the promoters. X-ray diffraction (XRD) analysis indicated that the main reflections were consistent wit...

Colloidal synthesis routes have been recently used to fabricate heterogeneous catalysts with more controllable and homogeneous properties. Herein a method was developed to modify the surface composition of colloidal nanocrystal catalysts and to purposely introduce specific atoms via ligands and change the catalyst reactivity. Organic ligands adsorbed on the surface of iron oxide catalysts were ...

Vanillin is one of the most commonly used natural products, which can also be produced from lignin-derived feedstocks. The chemical synthesis of vanillin is well-established in large-scale production from petrochemical-based starting materials. To overcome this problem, lignin-derived monomers (such as eugenol, isoeugenol, ferulic acid etc.) have been effectively used in the past few years. How...

The aim of this study was to obtain nanocrystalline mixed metal-oxide-ZrO₂ catalysts via a sonochemically-induced preparation method. The effect of a stabiliser's addition on the catalyst parameters was investigated by several characterisation methods including X-ray Diffraction (XRD), nitrogen adsorption, X-ray fluorescence (XRF), scanning electron microscopy (SEM) equipped with energy dispers...

Spent catalysts are principally solid waste which that coming out from nitrogenous fertilizer industry, during the production of ammonia, resulting in the production of large amount of solid waste containing nickel, which is the spent or deactivated catalysts. These catalysts contain from 12-14% nickel based on the production process in fertilizer industry disposal of spent catalyst is a proble...

Most physiological and biotechnological processes rely on molecular recognition between chiral (handed) molecules. Manmade homogeneous catalysts and enzymes offer complementary means for producing enantiopure (single-handed) compounds. As the subtle details that govern chiral discrimination are difficult to predict, improving the performance of such catalysts often relies on trial-and-error pro...

Iron-based catalysts were prepared by using promoters (K, Ru, Cu) and synthesis and activation protocols that inhibit sintering of oxide precursors and favor the nucleation of small Fe carbide crystallites. The effects of promoters on reduction/carburization behavior, on Fischer–Tropsch synthesis (FTS) rates, and on the number of CO binding sites formed during reaction were examined by combinin...

Poly(methylhydrosiloxane) (PMHS) supported organic catalysts promoted the Diels-Alder reaction of dienes with α,β-unsaturated aldehydes, also in pure water, in yields and enantiomeric excesses comparable to those observed with the non-supported catalysts (up to 93% ee). Recycling of the catalysts was performed with no loss of enantioselectivity for at least five reaction cycles.

reactants, reagents, and catalysts. A wide variety of performances of transition-metal catalysts are considerably dependent on the electronic states belonging to d-orbital electrons having dif ferent oxidative or spin states designed by coordinated ligands. To explore high-performance catalysts, analytical investigation based on electronic states is necessary, and theoretical calculations are i...