Preparation, characterization and catalytic activity of a nano-Co(II)-catalyst as a high efficient heterogeneous catalyst for the selective oxidation of ethylbenzene, cyclohexene, and benzyl alcohol

Synthesis and characterization of a lactose-based biosurfactant by a novel nanodendritic catalyst and evaluating its efficacy as an emulsifier in a food emulsion system

Nonionic lactose fatty acid esters are a class of synthetic biosurfactants with various uses in the food, pharmaceutical, personal care, and cosmetic industries. The objective of this research was the preparation and full characterization of a series of novel metallic encapsulated magnetic core/dendrimer shell composites as catalysts (CoII/MnII G2.0L1/2@SCMBNP) and their use in the chemo- and regioselective synthesis of a biosurfactant for the first time. Surface-active properties (such as contact angle (CA), surface tension (SFT), interfacial tension (IFT), critical micelle concentration (CMC), hydrophilic-lipophilic balance (HLB), foamability (FA) & foam stability (FS), emulsion ability (EmA) & emulsion stability (EmS), surface excess (Γ) and free energy of adsorption (ΔG) were also determined for all synthesized biosurfactants. In comparison to other works, these results suggested that the synthesized lactose fatty acid esters have potential application as synthetic emulsifiers featuring surface properties and are comparable with Ryoto sugar ester L-1695 (sucrose laurate) & Tween-20 (polysorbate 20) as industrial emulsifiers. The optimized conditions for biosurfactant syntheses are 8 days at 2 : 1 molar ratio of lactose sugar to lauric acid at 50 °C. Lactose ester as a biosurfactant exhibited a decrease of SFT & IFT and was able to stabilize a 20% soybean O/W emulsion. Furthermore, high conversion & yield, excellent chemo- and regioselectivity, and high operational stability over 5 runs were achieved for CoII/MnII-G2.0L1/2@SCMBNP, indicating the suitable efficiency of the catalytic process.

Super-magnetization of Co-pectin/gelatin biocomposite for selective synthesis vitamin K3: Design, fabrication and revealing role of the stabilizers

High pollution and low productivity of the traditional method for synthesis of vitamin group K require an efficient, low-cost, and environmentally sustainable biocatalyst as a greener process. These have encouraged us to design and fabricate a series of novel Co NPs impregnated pectin-gelatin (Co@PTNC, Co@GTNC & Co@PT_0.7GT_0.3NC) and grafted pectin-gelatin modified magnetic beads (Co@MPT_0.7GT_0.3NC) by the in situ reduction-precipitation procedure and chemical application in the selective synthesis of vitamin K3 without any promoters or ligands. The chemical structure and morphological properties were fully characterized. Additionally, the influence of structural parameters (i.e., kind of stabilizer with different ratio (n_PT/n_GT), amount of Co loading, durability, size, distribution, and Leaching test) and operating parameters (i.e., reaction time, reaction temperature, nature of the solvent, and concentration of oxidant) on the efficacy of the biocatalysts was evaluated in detail. The green synthesis involves several advantages, like the heterogeneous nature of catalysts, environmentally-friendly and mild conditions, high recovery efficiency due to superparamagnetism, high activity, and the sustainable performance of the biocatalyst.

Cu(ii) Schiff base complex intercalated into layered double hydroxide for selective oxidation of ethylbenzene under solvent-free conditions

A new heterogeneous catalyst was prepared by intercalation of NNOO donor Cu(ii) Schiff base complex derived from 2-hydroxy-1-naphthaldehyde and 4-amino benzoic acid into Zn–Al layered double hydroxide {LDH-[NAPABA–Cu(ii)]}. Synthesized catalyst was characterized by Inductively coupled plasma atomic emission spectroscopy, energy dispersive X-ray analysis, scanning electron microscopy, X-ray diffraction, Transmission electron microscopy, BET surface area, Fourier transform infrared spectroscopy, thermo-gravimetric analysis, electron paramagnetic resonance spectroscopy and diffuse reflectance UV-visible spectroscopy. The catalytic performance of LDH-[NAPABA–Cu(ii)] was studied for the liquid phase solvent-free oxidation of ethylbenzene at 393 K, using tert-butylhydroperoxide as an oxidant. In oxidation reaction ethylbenzene was oxidized to acetophenone, benzaldehyde and benzoic acid. The major product was acetophenone. A maximum, 80.54% conversion of ethylbenzene was observed after 7 hours. The catalyst was recycled seven times without significant loss of catalytic activity.

A heterogeneous catalytic system, LDH-[NAPABA–Cu(ii)]/TBHP gave maximum 80.54% conversion and 99.60% selectivity for acetophenone in oxidation of ethylbenzene and catalyst can be reused for seven cycles.

Ultrasound promoted preparation of Mn(III)-porphyrin nanoparticles: An efficient heterogeneous catalyst for oxidation of alkenes, alkanes and sulfides

In the present research meso-tetrakis(4-carboxyphenyl)porphyrinatomanganese(III) acetate (Mn(TCPP)OAc) nanoparticles have been prepared for the first time without any stabilizing agent or supporting matrix under ultrasonic irradiation. Scanning electron microscopy (SEM) was used to characterize and investigate the nanocatalyst. Rapid, efficient, facile and highly selective oxidation of a wide range of olefins by tetra-[Formula: see text]-butylammonium hydrogen monopersulfate over the prepared manganese nanocatalyst was investigated. Also oxidation of sulfides and alkanes in the presence of the (Mn(TCPP)OAc) nanoparticles were studied. The catalyst is recovered by filtration and reused at least five times.

Highly efficient Ni–Co oxide nanoparticles on nitrogen-doped FDU-15 for aerobic benzyl alcohol oxidation

Transition bimetal (Ni, Co) oxide nanoparticles immobilized onto nitrogen-doped FDU-15 are high active and show excellent selectivity to the benzaldehyde for the oxidation of benzyl alcohol.

Fe3O4 magnetic nanoparticles (MNPs) as an efficient catalyst for selective oxidation of benzylic and allylic C–H bonds to carbonyl compounds with tert-butyl hydroperoxide

Fe₃O₄ MNP as an eco-friendly catalyst was prepared, characterized and applied for oxidation of benzylic and allylic C–H bonds.

Co(ii), a catalyst for selective conversion of phenyl rings to carboxylic acid groups

We describe the use of Co(ii) in the presence of Oxone to effectively catalyze the conversion of –C₆H₅ to –COOH groups with a broad substrate scope, selectivity and under mild conditions.