Layered perovskite-like Sr2TiO4 is a promising catalyst for oxidative coupling of methane (OCM)—a potential direct route to produce C2 (ethane + ethylene) hydrocarbons, especially, ethylene. In this work, Sr2 – хLnxTi1 – yFeyO4 (Ln = La, Pr, х = 0, 0.1; y = 0–0.3) layered perovskites with partially substituted positions of Sr (La, Pr) or Ti (Fe), were synthesized by sol–gel method using polymeric precursors and wetness impregnation followed with calcination at 900–1000°C. The samples were characterized by X‑ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), X-ray photoelectron spectroscopy (XPS), adsorption and temperature-programmed hydrogen reduction (H2-TPR). It was revealed that Sr2TiO4 doping with La leads to formation of nanocomposite material containing Sr2TiO4, La‑doped SrTiO3 and La2O3 while Sr2TiO4, Sr3Ti2O7 and Pr6O11 are observed in the case of Pr. Fe–doped samples with x = 0.1–0.2 are the single-phase systems. Testing of the obtained doped materials in oxidative coupling of methane has shown the correlation of their catalytic activity with H2-TPR data and also with the ratio O_2^2 - /O2– (the surface adsorbed and surface lattice oxygen, correspondingly) and peculiarities of O2–. The higher СН4 conversion and C2 selectivity for the La-doped catalyst is due to appearance of O2– reduced at medium temperature. The low activity of Pr and Fe doped samples is conditioned by the presence of a large amount of surface adsorbed oxygen O_2^2 - facilitating COx formation and decreasing C2 selectivity.
The Diels–Alder (DA) reaction between 3-methyl-3-penten-2-one (MP) and myrcene is experimentally examined and theoretically modeled as part of the Iso E Super synthesis process. The results reveal that the DA reaction between MP and myrcene follows a typical electron-demand mechanism, and the para-product (2) is the most stable structure. With the addition of the AlCl3 catalyst, the reaction energy barrier drops significantly from 132.85 to 61.38 kJ/mol, easing the reaction conditions. The AlCl3 catalyst exhibits the highest catalytic activity among the catalysts tested, especially in isooctane solvent, of which the conversion of myrcene reaches 88.51
Anderson-type sodium hexamolybdoaluminate(III) is used for the synthesis of quinoxaline derivatives using 1,2-diketone and 1,2-diamine in aqueous medium at room temperature. This catalyst is characterized by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and thermogravimetric analysis (TGA). The Al(III) catalyst is a heterogeneous catalyst that was successfully recovered and recycled four times without major loss of activity. The methodology is environmentally benign and offers excellent product yields. The (Na3[AlMo6O24H6]·8H2O) is biologically evaluated for its cytotoxic activity against human breast adenocarcinoma cell lines. This catalyst exhibited moderate cytotoxic activity compared to the standard drug 5‑fluorouracil (5-FU), with a cell viability of 62.48
Al1 – xMgxCr2O4 nanochromites, where x = 0, 0.02, 0.04, 0.06, 0.08, and 0.10, were synthesized by citrate gel auto combustion technique. The X-ray diffraction study confirms the synthesized nanochromites belong to the spinel structure with the FD3M space group, and the average crystallite size was 20 to 24 nm, which was calculated from the Debye–Scherrer formula. The distribution of these sizes would be seen in the SEM pictures, providing light on the uniformity. About 550 and 625 cm–1 wavenumber domain FTIR bands are present in the FTIR spectrum, which correlate to the metal-oxygen bonds stretching vibrations of the octahedral (Mg–O bond linkage) and tetrahedral (Cr–O or Al–O bond linkage) sites. Using Tauc plots, the bandgap energy of the material was calculated, i.e., in between 2.21–3.26 eV. Fluorescence (FL) emission in the 400 nm region was seen in the PL spectra. Two organic industrial pollutants, such as Methylene Blue (MB) and Acid Red 18 (AR18), were utilized to examine the photocatalytic activity under visible light. Anticancer activity of Al1 – xMgxCr2O4 nanochromites tested with HeLa CCL2 cells. Antibacterial activity is carried out by two gram-positive and two gram-negative bacterial agents, namely Staphylococcus aureus (ATCC6538), Bacillus subtilis (ATCC11774), Escherichia coli (ATCC8739), and Klebsiella pneumoniae (ATCC10031). Antifungal activity is investigated by two fungal pathogens (candida albicans (ATCC10231) and Aspergillus niger (ATCC1015)) by a pour plate method.
Alkyl furfuryl ethers are promising additives to motor fuels, which can be produced by reductive etherification of furfural with alkyl alcohol. The Cu/Al2O3 catalyst was prepared using a copper ammonia complex as the precursor of active component. The catalytic behavior of the physical mixture of the Cu/Al2O3 catalyst and ZSM-5-Al2O3 composite was studied in the reductive etherification of furfural in a flow reactor using H2 as a reducing agent. This process involves the sequential hydrogenation of furfural on the Cu0 sites of the Cu/Al2O3 catalyst, followed by the etherification of the resulting furfuryl alcohol on the acid sites of zeolite. The highest yield of 2‑(isopropoxymethyl)furan (IMF) of 85
