00845nas a2200157 4500008004100000245007000041210006900111260000800180300001400188490000700202520031700209100002300526700001900549700002700568856009200595 2015 eng d00aChemical utilisation of CO2 a challenge for the sustainable world0 aChemical utilisation of CO2 a challenge for the sustainable worl cFEB a165–1760 v203 a

We derive more than 80% of our energy and chemicals from fossil fuels such as oil, coal and natural gas. Depleting resources and environmental pollution are forcing us to look for alternative resources. Carbon dioxide (CO2), which is produced in large quantities, could be recycled to chemical feedstocks.

1 aJagadeesan, Dinesh1 aJoshi, Bhaskar1 aParameswaran, Prashant uhttps://library.ncl.res.in/content/chemical-utilisation-co2-challenge-sustainable-world01718nas a2200169 4500008004100000022001400041245010300055210006900158260011000227300001600337490000600353520100600359100001401365700001801379700002301397856012801420 2015 eng d a2046-206900aPreparation of mesoporous titanosilicate with isolated Ti active centers for cyclohexene oxidation0 aPreparation of mesoporous titanosilicate with isolated Ti active aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcOCT a92371-923770 v53 a

We report the preparation of mesoporous titanosilicate with active Ti centres using CTAB as the structure directing agent and ethylenediamine as the complexing agent (TSC-ED). The finalmaterial contained isolated Ti4+ centres substituting Si4+ in the mesoporous silica framework. The crucial role played by ethylenediamine in complexing with Ti4+ during the sol-gel process and preventing the phase segregation of TiO2 was studied systematically. The textural parameters, structural order, morphology, nature and co-ordination of Ti species were analyzed using various techniques such as X-ray diffraction (XRD), UV-vis diffused reflectance spectroscopy (UV-vis DRS), UV resonance Raman spectroscopy, Fourier transformed Infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transition electron microscopy (TEM), and X-ray photoelectron spectroscopy. Finally, the catalysts were tested for catalytic activity in the oxidation of cyclohexene using various oxidants.

1 aGupta, S.1 aVinod, C., P.1 aJagadeesan, Dinesh uhttps://library.ncl.res.in/content/preparation-mesoporous-titanosilicate-isolated-ti-active-centers-cyclohexene-oxidation-001795nas a2200157 4500008004100000022001400041245009600055210006900151260011000220300001400330490000600344520112300350100001701473700002301490856012401513 2015 eng d a2044-475300aTunable acid-base bifunctional catalytic activity of FeOOH in an orthogonal tandem reaction0 aTunable acidbase bifunctional catalytic activity of FeOOH in an  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAY a4029-40380 v53 a

In this report, we have explored the acid-base bifunctional catalytic activity of iron oxohydroxides (FeOOH) by catalyzing deacetalization and Henry condensation reactions successively in a single pot. The crystalline polymorphs of FeOOH, namely goethite (alpha FeOOH), akaganeite (beta FeOOH), lepidocrocite (gamma FeOOH) and delta FeOOH, were chemically prepared and tested for the catalytic activity. All the polymorphs of FeOOH exhibited acid-base bifunctional catalytic activity. The relative selectivity for products varied with the polymorphs of FeOOH. Whereas alpha FeOOH produced benzaldehyde in high yield, the polymorphs beta FeOOH, gamma FeOOH and delta FeOOH showed high selectivity for trans-beta-nitrostyrene. In addition, beta FeOOH also exhibited a unique activity towards the formation of 1,3-dinitro-2-phenylpropane. The difference in the catalytic activity of FeOOH polymorphs was explained based on the strength and density of acidic and basic active sites on the surface. Selectivity for the products was tuned by changing the synthesis parameters of the catalysts and reaction conditions.

1 aVernekar, D.1 aJagadeesan, Dinesh uhttps://library.ncl.res.in/content/tunable-acid-base-bifunctional-catalytic-activity-feooh-orthogonal-tandem-reaction-002039nas a2200265 4500008004100000022001400041245013000055210006900185260007100254300001600325490000600341520103000347653001901377653003001396653001801426653002101444653001901465653003701484100002601521700002301547700002001570700002301590700002901613856013101642 2016 eng d a1944-824400aEarth abundant iron-rich N-doped graphene based spacer and cavity materials for surface plasmon-coupled emission enhancements0 aEarth abundant ironrich Ndoped graphene based spacer and cavity  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY a12324-123290 v83 a

We demonstrate for the first time the use of Fe based nanoparticles on N-doped graphene as spacer and cavity materials and study their plasmonic effect on the spontaneous emission of a radiating dipole. Fe-C-MF was produced by pyrolizing FeOOH and melamine formaldehyde precursor on graphene, while Fe-C-PH was produced by pyrolizing the Fe-phenanthroline complex on graphene. The use of the Fe-C-MF composite consisting of Fe-rich crystalline phases supported on N-doped graphene presented a spacer material with 116-fold fluorescence enhancements. On the other hand, the Fe-C-PH/Ag based cavity resulted in an 82-fold enhancement in Surface Plasmon-Coupled Emission (SPCE), with high directionality and polarization of Rhodamine 6G (Rh6G) emission owing to Casimir and Purcell effects. The use of a mobile phone as a cost-effective fluorescence detection device in the present work opens up a flexible perspective for the study of different nanomaterials as tunable substrates in cavity mode and spacer applications.

10aCasimir effect10afluorescence enhancements10airon carbides10aN-doped graphene10aPurcell factor10asurface plasmon-coupled emission1 aSrinivasan, Venkatesh1 aVernekar, Dnyanesh1 aJaiswal, Garima1 aJagadeesan, Dinesh1 aRamamurthy, Sai, Sathish uhttps://library.ncl.res.in/content/earth-abundant-iron-rich-n-doped-graphene-based-spacer-and-cavity-materials-surface-plasmon01328nas a2200157 4500008004100000245011800041210006900159260000800228300001200236490000600248520072700254100001800981700002000999700002301019856012801042 2016 eng d00aFine tuning the composition and nanostructure of Fe-based core-shell nanocatalyst for efficient CO2 hydrogenation0 aFine tuning the composition and nanostructure of Febased coreshe cOCT a989-9960 v23 a

Hydrogenation of CO2 to hydrocarbons is one of the crucial technologies to address the energy deficit and increasing environmental pollution. In this work, we have synthesized and systematically studied the influence of composition and nanostructure of a Fe-based, carbon-coated core shell nanocatalyst. The synthesis method offered good control over the thickness of the carbon coating in the core shell catalyst, which in turn controlled the chemical composition of the core. The results emphasized an optimal amount of Fe3O4, Fe5C2 in the core and partially graphitized carbon in the shell for a high catalytic activity in the conversion of CO2 at atmospheric pressure with higher selectivity to C-2-C-4 olefins.

1 aGupta, Sharad1 aJain, Vivek, K.1 aJagadeesan, Dinesh uhttps://library.ncl.res.in/content/fine-tuning-composition-and-nanostructure-fe-based-core-shell-nanocatalyst-efficient-co201784nas a2200193 4500008004100000022001400041245008500055210006900140260007300209300001000282490000800292520104000300653002801340653003401368653002901402653002101431100002301452856011501475 2016 eng d a0926-860X00aMultifunctional nanocatalysts for tandem reactions: a leap toward sustainability0 aMultifunctional nanocatalysts for tandem reactions a leap toward aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB a59-770 v5113 a

Design of new multifunctional nanocatalysts is a hot area of research that aims to introduce multiple types of active sites on a single nanocatalyst. Multifunctional nanocatalysts are useful to carry out a multi-step reaction requiring same or different active sites in a single pot. Such catalysts must possess the active sites at spatially distinct locations to avoid neutralization but yet remain active independently or through cooperative actions. The necessity of nanostructuring the active sites have emerged as the key point in a successful design of the catalysts. The review covers the progress in this area of research done in the last five years. It includes the classification of catalysts based on active sites and structure of active sites at the nanoscale. The review covers exhaustively with 250+ references and ample examples to present the concept succinctly. The review covers the evolution of multifunctional catalysts from the perspective of materials chemistry. (C) 2015 Elsevier B.V. All rights reserved.

10aHeterogeneous catalysts10aMultifunctional nanocatalysts10aNanostructured materials10aTandem reactions1 aJagadeesan, Dinesh uhttps://library.ncl.res.in/content/multifunctional-nanocatalysts-tandem-reactions-leap-toward-sustainability-001188nas a2200169 4500008004100000245011900041210006900160260000800229300001400237490000700251520053500258100002000793700003000813700002300843700002500866856012700891 2016 eng d00aSustainable Iron-catalyzed direct imine formation by acceptorless dehydrogenative coupling of alcohols with amines0 aSustainable Ironcatalyzed direct imine formation by acceptorless cMAY a3232-32380 v183 a

The Acceptorless Dehydrogenative Coupling (ADC) of alcohols with amines is reported using a heterogeneous Fe-catalyst. The reaction operates under mild conditions with the liberation of dihydrogen and water as the byproducts. The developed ADC strategy is simple, efficient, exhibits wide functional group tolerance and can be scaled up. The present catalytic approach possesses a dual role; acting as a catalyst as well as being magnetically separable. The sustainable reuse of a heterogeneous iron catalyst is also shown.

1 aJaiswal, Garima1 aLandge, Vinod, Gokulkrish1 aJagadeesan, Dinesh1 aBalaraman, Ekambaram uhttps://library.ncl.res.in/content/sustainable-iron-catalyzed-direct-imine-formation-acceptorless-dehydrogenative-coupling01693nas a2200169 4500008004100000245007500041210006900116260000800185300002500193490000600218520110700224100002001331700002201351700002301373700002501396856010201421 2017 eng d00aIron-based nanocatalyst for the acceptorless dehydrogenation reactions0 aIronbased nanocatalyst for the acceptorless dehydrogenation reac cDEC aArticle Number: 21470 v83 aDevelopment of sustainable catalytic systems for fundamentally important synthetic transformations and energy storage applications is an intellectually stimulating challenge. Catalytic dehydrogenation of feedstock chemicals, such as alcohols and amines to value-added products with the concomitant generation of dihydrogen is of much interest in the context of hydrogen economy and is an effective alternative to the classical oxidation reactions. Despite a number of homogeneous catalysts being identified for the acceptorless dehydrogenation, the use of high price and limited availability of precious metals and poor recovery of the catalyst have spurred interest in catalysis with more earth-abundant alternatives, especially iron. However, no report has described a reusable iron-based heterogeneous catalyst for oxidant-free and acceptorless dehydrogenation reactions. Here we replace expensive noble metal catalysts with an inexpensive, benign, and sustainable nanoscale iron catalyst for the efficient acceptorless dehydrogenation of N-heterocycles and alcohols with liberation of hydrogen gas.1 aJaiswal, Garima1 aLandge, Vinod, G.1 aJagadeesan, Dinesh1 aBalaraman, Ekambaram uhttps://library.ncl.res.in/content/iron-based-nanocatalyst-acceptorless-dehydrogenation-reactions01548nas a2200181 4500008004100000245009200041210006900133260000800202300001400210490000700224520090300231100002001134700002301154700002001177700002301197700002601220856012001246 2017 eng d00aIron-carbon nanohybrid particles as environmentally benign electrode for supercapacitor0 aIroncarbon nanohybrid particles as environmentally benign electr cFEB a1665-16740 v213 a

In this work, we report the synthesis and electrode applications of iron-carbon nanohybrid particles prepared by carbonization of a nanocomposite of FeOOH nanoneedles and melamine-formaldehyde resin. The chemical composition and microstructure of the material have been characterized using ICP-AES, FT-IR, XRD, FESEM, TEM and XPS. The supercapacitor properties of the MF-Fe-C are studied in detail. A thorough comparison of the supercapacitor performances of MF-Fe-C and bare MF-C has been carried out through detailed electrochemical characterisations employing both two and three-electrode techniques. The nanohybrid showed an enhanced energy density of 127.75 WhKg⁻¹, specific capacitance of ∼408 F g⁻¹ at 1 mVs⁻¹ scan rate, and excellent cyclic stability even after 1000 charge-discharge cycles, making it an intriguing material for high energy density supercapacitor devices.

1 aRatha, Satyajit1 aVernekar, Dnyanesh1 aSivaneri, Kavin1 aJagadeesan, Dinesh1 aRout, Chandra, Sekhar uhttps://library.ncl.res.in/content/iron-carbon-nanohybrid-particles-environmentally-benign-electrode-supercapacitor01549nas a2200181 4500008004100000022001400041245015200055210006900207260000900276300001400285490000600299520084200305100002301147700002001170700002501190700002301215856012901238 2019 eng d a2044-475300aEfficient bifunctional reactivity of K-doped CrO(OH) nanosheets: exploiting the combined role of Cr(iii) and surface -OH groups in tandem catalysis0 aEfficient bifunctional reactivity of Kdoped CrOOH nanosheets exp cMAR  a1154-11640 v93 a

This work reports the bifunctional catalytic activity of layered K-doped alpha-CrO(OH). The combined action of the redox active Cr(III) and the surface hydroxyl groups was efficiently used to carry out 2-3 oxidation reactions in tandem followed by condensation/coupling reactions in one pot. Oxidation of benzyl alcohol followed by Knoevenagel condensation or coupling reactions forming C-C and C-N linkages in one pot is demonstrated. The catalyst has been characterized using XRD, IR, TGA, CO2-TPD, cyclic voltammetry, XPS and microscopic techniques to gain insight into the nature of active sites. The role of O- and O2- on the CrO(OH) catalyst in the bifunctional activity was studied using analytical techniques. Recyclability and leaching tests confirmed that K-alpha-CrO(OH) is a stable and environmentally safe catalyst.

1 aVernekar, Dnyanesh1 aRatha, Satyajit1 aRode, Chandrashekhar1 aJagadeesan, Dinesh uhttps://library.ncl.res.in/content/efficient-bifunctional-reactivity-k-doped-crooh-nanosheets-exploiting-combined-role-criii01844nas a2200241 4500008004100000022001400041245010700055210006900162260000800231300001000239490000800249520099800257653002201255653002801277653002901305653001801334653002801352100002301380700002301403700002901426700002301455856012401478 2019 eng d a0021-951700aWater-promoted surface basicity in FeO(OH) for the synthesis of pseudoionones (PS) and their analogues0 aWaterpromoted surface basicity in FeOOH for the synthesis of pse cOCT a80-890 v3783 a

Use of Iron oxyhydroxide (gamma-FeO(OH)) as a robust catalyst for the synthesis of important intermediates like pseudoionones and their analogues through the C-C bond formation reactions like knoevenagel and aldol condensation is explored. These motifs are the building blocks for the construction of the sesquiterpenes as well as the diterpenes such as retinoic acid, Vitamin A etc. Iron oxyhydroxide (gamma-FeO(OH)) was synthesized and well characterized using XRD, FT-IR, TEM, XPS and adsorption studies to establish the catalytic activity. A thorough investigation on the nature of basic sites and the role of water as a promoter was explored based on dye adsorption, in situ methanol dissociation and CO2 adsorption studies. The catalyst also showed a wide range of substrate scope with active methylene groups involving various functional groups such as cyanides, esters and acetophenones along with its stability and reproducibility. (C) 2019 Elsevier Inc. All rights reserved.

10aBronsted basicity10aIron (III) oxyhydroxide10aKnoevenagel condensation10aPseudoionones10aSurface hydroxyl groups1 aVernekar, Dnyanesh1 aSakate, Sachin, S.1 aRode, Chandrashekhar, V.1 aJagadeesan, Dinesh uhttps://library.ncl.res.in/content/water-promoted-surface-basicity-feooh-synthesis-pseudoionones-ps-and-their-analogues02191nas a2200277 4500008004100000022001400041245012300055210006900178260000900247300001600256490000700272520125600279653001601535653002501551653002401576653003001600653002101630100002301651700002101674700002001695700000501715700001601720700002301736700002301759856013101782 2021 eng d a2155-543500aDirect oxidation of cyclohexane to adipic acid by a WFeCoO(OH) catalyst: role of bronsted acidity and oxygen vacancies0 aDirect oxidation of cyclohexane to adipic acid by a WFeCoOOH cat cSEP  a10754-107660 v113 aThis work reports the catalytic activity of the trimetallic mixed-metal oxyhydroxide WFeCoO(OH) for the direct oxidation of cyclohexane to adipic acid (AA) without the use of concentrated HNO3. WFeCoO(OH) displayed a 40% conversion of cyclohexane and a 67% selectivity to AA under relatively milder conditions of temperature (90 degrees C) and pressure (1 atm). Experimental evidence confirmed the presence of acidic, basic, and redox sites on WFeCoO(OH). The detailed investigation revealed that doping W in the Co-FeO(OH) matrix increased the amount of surface lattice oxygen (OS-L) and caused a significant surge in acidity (5.1 mmol/g). The calculated deprotonation energy of WFeCoO(OH) was 1434 kJ/mol, and the trend in acidity was WCoO(OH) < WFeCoO(OH) < FeCoO(OH) similar to CoO(OH). Energy calculations showed that WFeCoO(OH) had a high propensity to generate oxygen vacancies by the loss of either a water molecule or an oxygen atom (-132.2 or -140.9 kJ/mol, respectively). Basicity was generated due to the presence of conjugate pairs of the surface hydroxyl groups. The combined action of the trifunctional acidic, basic, and redox-active metal centers along with the oxygen vacancies was responsible for the enhanced catalytic performance.10aAdipic Acid10adeprotonation energy10ametal oxyhydroxides10amultifunctional catalysts10aoxygen vacancies1 aVernekar, Dnyanesh1 aDayyan, Mohammad1 aRatha, Satyajit1 a1 aHaider, Ali1 aKhan, Tuhin, Suvra1 aJagadeesan, Dinesh uhttps://library.ncl.res.in/content/direct-oxidation-cyclohexane-adipic-acid-wfecoooh-catalyst-role-bronsted-acidity-and-oxygen01889nas a2200181 4500008004100000022001400041245011200055210006900167260000800236300001600244490000800260520123600268100001801504700001701522700002301539700001801562856012701580 2023 eng d a1932-744700aMorphology-dependent catalysis by Co3O4 nanostructures in atmospheric pressure carbon dioxide hydrogenation0 aMorphologydependent catalysis by Co3O4 nanostructures in atmosph cJUL a13055-130640 v1273 a

In this work, three Co3O4 nanostructureswith different morphologies (cubes, rods, and sheets) were synthesizedusing a hydrothermal method and tested for the CO2 hydrogenationreaction. The physicochemical properties of the structured Co3O4 were well characterized by X-ray diffraction(XRD), Raman spectroscopy, field-emission scanning electron microscopy(FESEM), transmission electron microscopy (TEM), high-resolution transmissionelectron microscopy (HRTEM), hydrogen temperature-programmed reduction(H-2-TPR), and X-ray photoelectron spectroscopy (XPS) techniques.Based on the characterization, cube, rod, and sheet Co3O4 nanostructures were found to expose the (100), (110),and (112) planes, respectively. The effect of cobalt oxide morphologieswith different exposed surfaces on the activity and selectivity towardCO(2) hydrogenation reaction in a plug-flow reactor operatedbetween 200 and 400 & DEG;C under atmospheric pressure conditionswas explored. The results establish a correlation of the catalyticactivity with morphological structures in the order rods > sheets> cubes. H-2-TPR and XPS studies demonstrated that thehighreducibility of Co3O4 rod makes it an excellentcatalyst for CO2 hydrogenation.

1 aGupta, Sharad1 aJain, Preeti1 aJagadeesan, Dinesh1 aVinod, C., P. uhttps://library.ncl.res.in/content/morphology-dependent-catalysis-co3o4-nanostructures-atmospheric-pressure-carbon-dioxide02242nas a2200217 4500008004100000022001400041245011600055210006900171260000800240300001400248490000700262520148500269100001801754700002001772700002201792700001901814700002201833700001801855700002301873856012801896 2023 eng d a2044-475300aOxidation of ethylene by Cu/TiO2: reducibility of Cu2+ in TiO2 as a possible descriptor of catalytic efficiency0 aOxidation of ethylene by CuTiO2 reducibility of Cu2 in TiO2 as a cAPR a2330-23390 v133 a

Catalytic oxidation using non-noble metal-based catalysts is a promising approach to mitigate pollution due to VOCs in the air. In this work, mesoporous Cu/TiO2 catalysts containing different concentrations of Cu2+ (0.2, 1, 3, and 4 wt% Cu w.r.t. Ti) were synthesized using the sol-gel technique. The catalysts were characterized using inductively coupled plasma-optical emission spectrometry, XRD, Raman spectroscopy, N-2 physisorption, cyclic voltammetry, H-2-TPR and electron microscopy to understand the structure and composition. The thermal catalytic gas phase oxidation of ethylene was studied by heating a mixture of ethylene (1.5 vol%) and air (5.9 vol%) in the presence of the Cu/TiO2 samples in the temperature range of 298 to 773 K. Cu/TiO2 showed a higher catalytic activity compared to TiO2 for the thermal oxidation of ethylene, indicating a strong promotion by doped copper ions. A volcanic behaviour in the catalytic activity was observed with different concentrations of Cu doping, with 1% Cu/TiO2 showing a 99.5% ethylene conversion at 673 K and 100% selectivity to CO2. The activity of 1% Cu/TiO2 remained consistent without deactivation for 24 h. At low dopant concentrations of Cu (0.2 and 1% Cu/TiO2), the reduction of Cu2+ to Cu+ was observed. An interplay of oxygen vacancies (O-V), Cu+, Cu2+ and Ti4+ may be involved in controlling the activity. DRIFT studies indicated the formation of surface bidendate carbonate as a possible intermediate.

1 aRajendran, K.1 aSharma, Mandeep1 aJaison, Augustine1 aAnkitha, Menon1 aTiwari, Ankit, D.1 aVinod, C., P.1 aJagadeesan, Dinesh uhttps://library.ncl.res.in/content/oxidation-ethylene-cutio2-reducibility-cu2-tio2-possible-descriptor-catalytic-efficiency01981nas a2200193 4500008004100000022001400041245011900055210006900174260000800243300001400251490000600265520128500271100002201556700002601578700001801604700001601622700002301638856012601661 2024 eng d a2516-023000aFacile synthesis of nanostructured Ni/NiO/N-doped graphene electrocatalysts for enhanced oxygen evolution reaction0 aFacile synthesis of nanostructured NiNiONdoped graphene electroc cMAY a2813-28220 v63 a

Electrocatalysts containing a Ni/NiO/N-doped graphene interface have been synthesised using the ligand-assisted chemical vapor deposition technique. NiO nanoparticles were used as the substrate to grow N-doped graphene by decomposing vapours of benzene and N-containing ligands. The method was demonstrated with two nitrogen-containing ligands, namely dipyrazino[2,3-f:2 `,3 `-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (L) and melamine (M). The structure and composition of the as-synthesized composites were characterized by XRD, Raman spectroscopy, SEM, TEM and XPS. The composite prepared using the ligand L had NiO sandwiched between Ni and N-doped graphene and showed an overpotential of 292 mV at 10 mA cm-2 and a Tafel slope of 45.41 mV dec-1 for the OER, which is comparable to the existing noble metal catalysts. The composite prepared using the ligand M had Ni encapsulated by N-doped graphene without NiO. It showed an overpotential of 390 mV at 10 mA cm-2 and a Tafel slope of 78.9 mV dec-1. The ligand-assisted CVD route demonstrates a facile route to control the microstructure of the electrocatalysts. Electrocatalysts containing a Ni/NiO/N-doped graphene interface have been synthesised using the ligand-assisted chemical vapor deposition technique.

1 aMadampadi, Roshni1 aPatel, Avit, Bhogilal1 aVinod, C., P.1 aGupta, Ritu1 aJagadeesan, Dinesh uhttps://library.ncl.res.in/content/facile-synthesis-nanostructured-ninion-doped-graphene-electrocatalysts-enhanced-oxygen01795nas a2200181 4500008004100000022001400041245010900055210006900164260000800233300001600241490000700257520114000264100001801404700001801422700002301440700002301463856012701486 2025 eng d a0887-062400aHydrogenation of CO2 catalyzed by thermally decomposed cobalt-containing alkaline earth metal carbonates0 aHydrogenation of CO2 catalyzed by thermally decomposed cobaltcon cJUN a12982-129910 v393 a

CO2 hydrogenation over Co catalysts supported on alkaline earth metal oxides was investigated. The catalysts were prepared by thermally decomposing alkaline metal carbonates CoMCO3, where M = Mg, Ca, Sr, and Ba, in H2. During the thermal activation, contingent upon the thermal stability of the precursor, it transformed into a composite of metal oxides, metals, and undecomposed metal carbonates. The thermal activation temperature, the ratio of CO2 to H2, the composition, and the basicity of the catalyst all played a significant role in influencing the conversion of CO2 and the selectivity to CH4. Among the various Co-containing alkaline earth metal carbonate precursors, CoCaCO3 activated at 400 degrees C yielded the highest steady-state CO2 conversion of 54% with a CH4 selectivity of 89.8% throughout 28 h in the reaction stream containing a 1:4 ratio of CO2 and H2. Detailed characterization showed that the CaCo-400 catalyst contained metallic Co, CaO, and undecomposed CaCO3 phases. The study assumes significance in understanding the role of the composition of catalysts in the formation of CO2 hydrogenation.

1 aGupta, Sharad1 aVinod, C., P.1 aPoupin, Christophe1 aJagadeesan, Dinesh uhttps://library.ncl.res.in/content/hydrogenation-co2-catalyzed-thermally-decomposed-cobalt-containing-alkaline-earth-metal