04507nas a2200193 4500008004100000245009100041210006900132260000800201300001400209490000600223520382900229100002104058700002604079700002104105700002204126700002504148700002604173856011404199 2019 eng d00a Synthesis of biodiesel using the Mg/Al/Zn hydrotalcite/SBA-15 nanocomposite catalyst 0 aSynthesis of biodiesel using the MgAlZn hydrotalciteSBA15 nanoco cFEB a3500-35070 v43 a

Biodiesel production is an enchanting and eccentric pathway for the reduction of use of fossil fuels and is procured from biologically available renewable sources such as oils and fats. A novel Mg/Al/Zn-based hydrotalcite/SBA-15 composite material having a high catalytic activity was developed and investigated for the transesterification of vegetable oil. The rationally developed composites were systematically characterized and assessed in the transesterification of soybean oil in the presence of methanol. The physicochemical evaluation of the nanocomposites demonstrated the influence of Zn in the textural characteristics, density of the basic sites, and successively the catalytic activity. The catalytic efficiency of the MAZ-x/SBA-15 composite could be linked with the basic site density determined by the temperature-programmed desorption of CO2. Among all the composites used, the MAZ-1/SBA-15 nanocomposite showed the highest activity for biodiesels, with a yield of around 90% under economical reaction conditions. The catalytic studies conferred that the fatty acid methyl ester yield is significantly influenced by various experimental conditions such as the catalyst molar ratio, reaction temperature, pressure, and contact time. It was also found that the incorporation of hydrotalcite into SBA-15 pore channels can enhance the catalyst efficiency and stability of the nanocomposite. Moreover, under mild reaction conditions, a remarkably stable catalytic performance was achieved for more than 200 h of time on stream with no catalyst deactivation.
 

1 aPrabu, Marimuthu1 aManikandan, Marimuthu1 aKandasamy, Prabu1 aKalaivani, P., R.1 aRajendiran, Nagappan1 aRaja, Thirumalaiswamy uhttps://library.ncl.res.in/content/synthesis-biodiesel-using-mgalzn-hydrotalcitesba-15-nanocomposite-catalyst03096nas a2200301 4500008004100000245011200041210006900153260000800222300000800230490000700238520212000245653001102365653001402376653001802390653001402408653001502422653001402437653001702451653002602468100002302494700002102517700002402538700002602562700002902588700002102617700002602638856013002664 2022 eng d00aSynthesis and crystal structures of Mn(II) and Co(II) complexes as catalysts for oxidation of cyclohexanone0 aSynthesis and crystal structures of MnII and CoII complexes as c cJUL a1000 v103 a

The global demand on adipic usage in the production of plasticizers and synthetic polyamide is increasing. In line with the search for an efficient and energy-conserving way to isolate adipic acid (AA) in good yields, this paper introduces the oxidization of cyclohexanone utilizing two new coordination compounds, [Mn(2,6-pydc)(2)](imi) (1) and [Co(H(2)pza)(2)(H2O)(2)(NO3)].NO3 (2), as catalysts. Compounds 1 and 2 were synthesized by room temperature and refluxing methods, and characterized by spectral analyses (IR and UV-Vis.), SEM, BET, TGA, elemental, and X-ray crystallography. The single crystal structure of compound 1 revealed that pyridinedicarboxylate (2,6-pydc) and imidazole (imi) moieties were coordinated to the Mn(II) atom through imine nitrogen and deprotonated oxygen atoms, to form an undistorted octahedral coordination geometry with the N2O4 donor set. The axial and equatorial planes containing O2, O4, O5, and O7 atoms were from two adjacent 2,6-pydc ligands which formed the unidendate donor ligand; imi, on the other hand, acted as a bidendate donor ligand. For compound 2, the Co(II) atom was being coordinated by two pyrazinamide (H(2)pza) moieties, which acted as an unidendate donor ligand; two water molecules occupying the axial position, and one nitrate molecule occupying the apical position, were within the coordination sphere; a nitrate molecule was disordered outside the coordination sphere. The distance, 4.658 angstrom, between the Co1 atom and the N8 atom of the uncoordinated nitrate molecule, was within the range reported elsewhere. Cyclohexanone peroxidation experiments revealed that compound 1 exhibited unique catalytic performance by giving a 72.8% yield in adipic acid, in comparison to the 71.3% yield obtained with compound 2. The yields in AA were maintained by way of recyclability evaluation. The reaction kinetics of compound 2 gave less activation energy, E-a 2938 J mol(-1), while the thermodynamic parameters indicated that the chemical reactivity of cyclohexanone on the active surfaces of compounds 1 and 2 was via monolayer physisorption.

10acobalt10aComplexes10acyclohexanone10aImidazole10amanaganese10aOxidation10apyrazinamide10apyridinedicarboxylate1 aTella, Adedibu, C.1 aIsaac, Aaron, Y.1 aClayton, Hadley, S.1 aOgunlaja, Adeniyi, S.1 aVenugopalan, Aswathy, T.1 aPrabu, Marimuthu1 aThirumalaiswamy, Raja uhttps://library.ncl.res.in/content/synthesis-and-crystal-structures-mnii-and-coii-complexes-catalysts-oxidation-cyclohexanone