02076nas a2200205 4500008004100000245008600041210006900127260000800196300001200204490000800216520133700224100002101561700002101582700002801603700003701631700002801668700003001696700002601726856011801752 2016 eng d00aEffective and selective oxidation of 2-butanol over Mn supported catalyst systems0 aEffective and selective oxidation of 2butanol over Mn supported  cSEP a237-2460 v5253 a

Oxidation of alcohols to their corresponding aldehydes/ketones is an important reaction in industries as well as in academic perspective. Selective oxidation (Selox) of alcohols like methanol, ethanol and propanol are well studied in literature; however, alcohols like butanol, pentanol, octanol is a challenging task. Selective oxidation of 2-butanol to methyl ethyl ketone (MEK) is an important reaction due to its wide range of applications. Herein, we demonstrated the selective oxidation of 2-butanol to MEK over Mn supported on different oxide supports. A series of MnxOy-Al2O3 (MA), MnxOy-CeO2 (MC), MnxOy-ZrO2 (MZ) and MnxOy-SiO2 (MS) catalysts were prepared by co-precipitation followed by hydrothermal method. As synthesised catalysts were characterised by various physico-chemical characterisation techniques. It was found that the presence of Mn3O4 species in MA and MZ catalysts is responsible for maximum catalytic activity towards 2-butanol oxidation. MA catalyst conferred a maximum 2-butanol conversion of 51% and 88% selectivity towards MEK. XPS analysis revealed that Mn in MA catalyst exists in +2 and +3 oxidation states and responsible for 2-butanol oxidation. Moreover it was found that the acidity of the catalyst also plays an important role in catalytic activity. (C) 2016 Published by Elsevier B.V.

1 aPrabu, Kandasamy1 aPrabu, Marimuthu1 aVenugopal, Ashok, Kumar1 aVenugopalan, Aswathy, Thareparam1 aSandilya, W., V. Y. Sai1 aGopinath, Chinnakonda, S.1 aRaja, Thirumalaiswamy uhttps://library.ncl.res.in/content/effective-and-selective-oxidation-2-butanol-over-mn-supported-catalyst-systems02019nas a2200193 4500008004100000022001400041245012500055210006900180260000800249300001000257490000800267520129700275100002601572700002101598700002401619700002601643700003201669856012401701 2018 eng d a2468-823100aTuning the basicity of Cu-based mixed oxide catalysts towards the efficient conversion of glycerol to glycerol carbonate0 aTuning the basicity of Cubased mixed oxide catalysts towards the cDEC a53-620 v4603 aA series of efficient and robust Cu based mixed oxides were synthesized by a simple co-precipitation method and utilized for the production of glycerol carbonate (GC) via transesterification of glycerol with dimethyl carbonate (DMC). The synthesized materials were characterized using XRD, UV-vis spectroscopy, SEM, TEM, N-2 sorption, CO2-TPD, and XPS. The addition of Cu on Mg/Al mixed oxides exhibits significant changes in its physicochemical properties and catalytic activity. The obtained mixed oxides showed remarkably high transesterification activity towards the efficient conversion of glycerol to GC under economical reaction conditions without using any solvent. Among all the catalysts employed, highest catalytic activity was observed over MAC-0.6 catalyst with glycerol conversion of 96.4% and GC yield of 91.2%. The improved catalytic performance was observed mainly due to the optimized catalyst molar ratio and strong surface basicity. The strong surface basic sites were greatly attributed to the incorporation of Cu2+ cations in the MgAl (O) periclase that efficiently catalyzed the transesterification of glycerol with DMC. Furthermore, the reported catalyst was robust and could be recycled for more than five times without any significant loss in its catalytic activity.1 aManikandan, Marimuthu1 aPrabu, Marimuthu1 aKumar, S., K. Ashok1 aSangeetha, Palanivelu1 aVijayaraghavan, Rajagopalan uhttps://library.ncl.res.in/content/tuning-basicity-cu-based-mixed-oxide-catalysts-towards-efficient-conversion-glycerol04507nas 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-catalyst02491nas a2200253 4500008004100000022001400041245014200055210006900197260000800266300001100274490000800285520163000293653001501923653001201938653001701950653001801967653001101985100002601996700002202022700002102044700002602065700002602091856012002117 2022 eng d a0921-510700aComparative investigation on the catalytic performance of HT/SBA-15 and SBA-15/HT composites for the isomerization of glucose to fructose0 aComparative investigation on the catalytic performance of HTSBA1 cDEC a1160520 v2863 a

Hydrotalcites (HT) have a broad spectrum of applications as prosperous heterogeneous catalysts for diverse chemical transformations. The catalytic activity of HT-based materials can be tailored by introducing siliceous material into the internal or external framework. The surface modification of the HT framework with silica mesostructures leads to the formation of versatile Lewis base, Bronsted base and redox catalytic active sites. This work presents the comparative evaluation of the catalytic performance of HT/SBA-15 and SBA-15/HT composites for the isomerization of glucose to fructose using 1-butanol as a solvent. The composites with different external morphology were prepared by a modified template-assisted hydrothermal method, using different HT to SBA-15 proportions. The textural and morphological characterization results conferred the efficiency of the employed post-synthetic intercalation strategy to achieve the successful formation of HT/SBA-15 and SBA-15/HT composites. With optimal HT loading and surface basicity, the HTS-3 composite demonstrated the highest catalytic performance, resulting in good glucose conversions (54 %) with improved selectivity (>83 %). The observed high reactivity could be mainly attributed to the extensive dispersion of HT particles on the SBA-15 component, which contributes to a significant increase in textural properties and surface basicity. Furthermore, special attention is devoted to addressing such reactivity phenomena as active site selectivity, catalyst multifunctionality and multisite reactivity commonly encountered in mesoporous catalysis.

10acomposites10aglucose10ahydrotalcite10aisomerization10aSBA-151 aManikandan, Marimuthu1 aArjunan, Ayyappan1 aPrabu, Marimuthu1 aRaja, Thirumalaiswamy1 aSangeetha, Palanivelu uhttps://library.ncl.res.in/content/comparative-investigation-catalytic-performance-htsba-15-and-sba-15ht-composites01592nas a2200289 4500008004100000022001400041245010800055210006900163260000800232300001100240490000800251520061400259653001600873653002700889653002200916653001700938100002500955700002100980700002701001700002301028700001901051700002901070700002201099700002601121700002601147856012901173 2022 eng d a1566-736700aGreen synthesis of cyclohexanone to adipic acid over Fe-W oxides incorporated mesoporous carbon support0 aGreen synthesis of cyclohexanone to adipic acid over FeW oxides  cAUG a1064660 v1683 a

We have prepared iron and tungsten oxides incorporated mesoporous carbon (MC) catalysts using a simple hydrothermal methodology with different carbon sources, and the catalytic performance was investigated for cyclohexanone oxidation. An adequate amount of metal oxide loading has displayed a key role in the selective catalyst for adipic acid (AA) synthesis. The MC catalyst has shown its prime activity under the influence of redox properties of W5+/W6+ and Fe2+/Fe3+ as promoters. The 10%Fe 90%W-MC fructose as a carbon source catalyst has provided its best selectivity of 87% for AA at 120 ?C.

10aAdipic Acid10aLiquid phase oxidation10amesoporous carbon10aRedox center1 aMekala, Siva, Prasad1 aPrabu, Marimuthu1 aGawali, Sheetal, Datta1 aGopakumar, Karthik1 aGogoi, Pranjal1 aBhatkar, Akash, Ravindra1 aMohapatra, Gourab1 aUnnikrishanan, Eeswar1 aRaja, Thirumalaiswamy uhttps://library.ncl.res.in/content/green-synthesis-cyclohexanone-adipic-acid-over-fe-w-oxides-incorporated-mesoporous-carbon03096nas 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-cyclohexanone02480nas a2200325 4500008004100000245010800041210006900149260000800218300001400226490000600240520139800246653001601644653002401660653002601684653002301710653001501733653001701748100002101765700002601786700002901812700002901841700002501870700002601895700002101921700002201942700001601964700002601980700002602006856012202032 2023 eng d00aMnXWO4 nanostructure-based catalysts for single-step oxidation of cyclohexane and methane to oxygenates0 aMnXWO4 nanostructurebased catalysts for singlestep oxidation of  cAPR a7245-72580 v63 a

Activation of the C-H bond in cyclohexane (CYH) and methane is a crucial step to obtain desirable oxygenated products using nanostructured catalyst and is a great challenge and an efficient route to mitigate the inauspicious effects of climate change. The active sites were identified using XRD, HR-TEM, SEM, N2 sorption analysis, TPR, Raman, XPS, TGA, in situ DRIFT, XAS, etc. In optimal reaction conditions, 46% of CYH was converted into adipic acid (AA) on MnxWO4 nanostructures within 6 h. The recyclability test confirmed the catalyst heterogeneity, which revealed no appreciable loss of catalytic activity even after three consecutive reactions. In situ DRIFT study reveals that CYH is oxidized to cyclohexanone and cyclohexanol (KA oil) and is further oxidized to AA via carboxylate intermediates. DFT studies disclosed that MnOx species are responsible for the C-H activation of CYH, and the Mn2+/Mn3+ redox centers play a vital role in the absorption of KA oil to form AA. Herein, we demonstrated the significant role of the ``MnOx'' species and that adequate Lewis and Bronsted acidic sites, redox centers of (Mn2+/Mn3+), and lattice oxygen are accountable for the CYH conversion toward the AA. Additionally, we have reported the oxidation of methane to methanol (146 mu mole per gram of catalyst) in the presence of water at 75 degrees C without over-oxidation products.

10aAdipic Acid10aC-H bond activation10aCyclohexane oxidation10amethane activation10aMnOx chain10aRedox center1 aPrabu, Marimuthu1 aManikandan, Marimuthu1 aSamal, Pragnya, Paramita1 aGurrala, Lakshmi, Prasad1 aMekala, Siva, Prasad1 aArchana, Ramakrishnan1 aNayak, Chandrani1 aBhattacharyya, D.1 aJha, S., N.1 aKrishnamurty, Sailaja1 aRaja, Thirumalaiswamy uhttps://library.ncl.res.in/content/mnxwo4-nanostructure-based-catalysts-single-step-oxidation-cyclohexane-and-methane01922nas a2200289 4500008004100000022001400041245012100055210006900176260000900245300001100254490000800265520098600273653001601259653002601275653001801301653001001319653001401329653001701343653000801360100002101368700001901389700002201408700002601430700002001456700002601476856013001502 2023 eng d a2468-823100aNitric acid free cyclohexane to adipic acid production using nickel and vanadium incorporated AlPO-5 molecular sieve0 aNitric acid free cyclohexane to adipic acid production using nic cAPR  a1130510 v5403 a

Rationally designing a stable and sustainable metal oxide supported over the molecular sieve catalysts for oxidizing cyclohexane (CYH) to adipic acid (AA) is vital in industrial applications. The in-situ hydrothermal synthesis method successfully incorporated vanadium and nickel into the aluminium phosphate-5 (AlPO-5) molecular sieves (MFI structure). The XPS and NH3 TPD analysis disclosed that the addition of Ni into V-AlPO-5 stabilizes the ratio of V4+/V5+, creating strong acidic sites and the formation of NiOOH, which are a vital role for the selective CYH oxidation to AA. An in-situ DRIFT study reveals that nickel takes part in the formation of dicarboxylate ions as an intermediate to form AA. Our catalytic studies profoundly suggested that the Ni0.1V0.2AlPO-5 catalyst used for CYH oxidation gives better selectivity towards AA (53%) in the presence of oxygen at an appropriate amount of solvent without an initiator or promoter within a short time (3h).

10aAdipic Acid10aCyclohexane oxidation10aIn situ DRIFT10aNiOOH10aNiVAlPO-510aRatios ofV4+10aV5+1 aPrabu, Marimuthu1 aSharma, Shweta1 aRaja, Abhishekram1 aArchana, Ramakrishnan1 aSamruddhi, Mane1 aRaja, Thirumalaiswamy uhttps://library.ncl.res.in/content/nitric-acid-free-cyclohexane-adipic-acid-production-using-nickel-and-vanadium-incorporated00931nas a2200265 4500008004100000022001400041245011100055210007000166260000800236490000700244653001600251653001500267653002100282100002400303700002600327700002100353700002300374700002600397700002600423700002200449700002300471700001900494700002600513856012600539 2024 eng d a2192-650600aTemperature-controlled hydrothermal synthesis of α-MnO2 nanorods for catalytic oxidation of cyclohexanone0 aTemperaturecontrolled hydrothermal synthesis of αMnO2 nanorods f cJUL0 v8910aAdipic Acid10aconversion10aMANGANESE OXIDES1 aJha, Ratnesh, Kumar1 aManikandan, Marimuthu1 aPrabu, Marimuthu1 aVineeth, Nidhi, R.1 aDharmalingam, Praveen1 aArchana, Ramakrishnan1 aHarsha, Murudappa1 aShankar, Sonu, Ram1 aBhatte, Kushal1 aRaja, Thirumalaiswamy uhttps://library.ncl.res.in/content/temperature-controlled-hydrothermal-synthesis-%CE%B1-mno2-nanorods-catalytic-oxidation02207nas a2200313 4500008004100000022001400041245013600055210006900191260000800260300001100268490000800279520114300287653002701430653002201457653002401479653001201503653002201515653001301537100002101550700002601571700002401597700002601621700002201647700002501669700001801694700002701712700002601739856012801765 2025 eng d a1385-894700aDeciphering the intricate mechanisms behind the selective oxidation of methane to C1 and C2 oxygenates over FeAu/γ-Al2O3 catalysts0 aDeciphering the intricate mechanisms behind the selective oxidat cMAY a1625100 v5123 a

In this work, we demonstrate an eco-benign synthesis protocol for preparing gold nanoparticles and the role of the strong interaction between gold nanoparticles and iron oxide in FeAu/gamma-Al2O3 catalysts that render it an anionic (Au delta-) character while tailoring them in a smaller size. The multifunctional FeAu/gamma-Al2O3 catalyst selectively produces ethanol (95 % selectivity, similar to 240 mu mol(-1) cat) at a mild temperature of 75 degrees C without the addition of co-reactants during liquid phase methane oxidation with molecular oxygen. Conversely, Au/gamma-Al2O3 and Fe/gamma-Al2O3 catalysts exhibited high selectivity for CH3OH and HCHO. A high dispersion accompanied by strong electronic interaction between the Au delta–FeOx, as corroborated by diverse techniques, enables methane activation across the interface and coupling on the gold nanoparticles, which are responsible for the markedly improved formation of ethanol. Furthermore, in situ DRIFTS studies and DFT investigations point to a reaction mechanism of coupling of CH2OH and CH3 intermediates as the most likely route for ethanol formation.

10aAnionic gold catalysts10aAu-FeOx synergism10aC-H bond activation10aEthanol10aMethane oxidation10aMethanol1 aPrabu, Marimuthu1 aManikandan, Marimuthu1 aRengam, Sathya, Sai1 aRamakrishnan, Archana1 aRaja, Abhishekram1 aUrkude, Rajashri, R.1 aGhosh, Biplab1 aVarghese, Jithin, John1 aRaja, Thirumalaiswamy uhttps://library.ncl.res.in/content/deciphering-intricate-mechanisms-behind-selective-oxidation-methane-c1-and-c2-oxygenates