01327nas a2200157 4500008004100000245011800041210006900159260000800228300001200236490000600248520072700254100001800981700002000999700002301019856012701042 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 uhttp://library.ncl.res.in/content/fine-tuning-composition-and-nanostructure-fe-based-core-shell-nanocatalyst-efficient-co201970nas a2200253 4500008004100000022001400041245017400055210006900229260000800298300001100306490000700317520104800324653002201372653002101394653002001415653002001435653002501455100001801480700002101498700002101519700002701540700001801567856013101585 2020 eng d a2352-940700aEngineering pore morphology using silica template route over mesoporous cobalt oxide and its implications in atmospheric pressure carbon dioxide hydrogenation to olefins0 aEngineering pore morphology using silica template route over mes cJUN a1005860 v193 a

Highly ordered mesoporous cobalt oxides (denoted as m-Co-KIT-6 and m-Co-SBA-15) with three dimensional and two dimensional pore morphology respectively have been synthesized using 3D KIT-6, and 2D SBA-15 as silica template via nanocasting route. CO2 hydrogenation activity was evaluated for these mesoporous materials under atmospheric pressure conditions. In comparison to nanoparticles of cobalt oxide (Co3O4-nano), mesoporous catalysts showed excellent activity for CO2 hydrogenation due to their higher number of exposed active sites and lower mass diffusion limitations. The ordered mesoporous structure of Co3O4 catalysts favored the chain growth of carbon atoms for the production of C2+ hydrocarbons while Co3O4 nanoparticles showed strong selectivity toward CH4. High selectivity for C2+ (similar to 25%) was obtained for both m-Co-KIT-6 and m-Co-SBA-15 catalysts at 320 degrees C. In addition, the 3D pore structure of m-Co-KIT-6 catalyst exclusively formed more olefins (54.9%) fraction. (C) 2020 Published by Elsevier Ltd.

10aCO2 hydrogenation10aMesoporous CO3O410aOlefin fraction10aPore morphology10aSilica hard template1 aGupta, Sharad1 aCiotonea, Carmen1 aRoyer, Sebastien1 aDacquin, Jean-Philippe1 aVinod, C., P. uhttp://library.ncl.res.in/content/engineering-pore-morphology-using-silica-template-route-over-mesoporous-cobalt-oxide-and-its01256nas a2200145 4500008004100000245008900041210006900130260000800199490000700207520073300214100001700947700001800964700001800982856011001000 2020 eng d00aRole of exposed crystal facets in the atmospheric pressure CO hydrogenation on Co3O40 aRole of exposed crystal facets in the atmospheric pressure CO hy cJUL0 v233 a

Co3O4 nanostructures with different exposed planes are studied for atmospheric pressure CO hydrogenation. Existence of different facets is characterized by HR-TEM and found Co3O4 - NSP (nanospheres) expose (112) facet, NB (nanobelts) exhibit (110) plane and (100) is the dominant surface facet in NC (nanocubes). Different catalytic activity is demonstrated by the specific facet of Co3O4 catalysts. CO hydrogenation is facet dependent and the catalytic activity follows the order of Co3O4-NB > Co3O4-NC > Co3O4-NSP.

1 aJain, Preeti1 aGupta, Sharad1 aVinod, C., P. uhttp://library.ncl.res.in/content/role-exposed-crystal-facets-atmospheric-pressure-co-hydrogenation-co3o403574nas a2200205 4500008004100000022001400041245006600055210006400121260000900185300001200194490000700206520292200213100001903135700002803154700001803182700002103200700002803221700002403249856009503273 2021 eng d a1528-748300aCan we identify the salt-cocrystal continuum state using XPS?0 aCan we identify the saltcocrystal continuum state using XPS cFEB  a735-7470 v213 a

X-ray photoelectron spectroscopy (XPS) is used to understand the nature of acid-base crystalline solids, to know whether the product is a salt (proton transfer, O-center dot center dot center dot H-N+) or a cocrystal (neutral adduct, O-H center dot center dot center dot N). The present study was carried out to explore if intermediate states of proton transfer from COOH to nitrogen (the proton resides between hydrogen bonded to O and N, O center dot center dot center dot H center dot center dot center dot N, quasi state) can be differentiated from a salt (complete proton transfer, N+-H center dot center dot center dot center dot O-) and cocrystal (no proton transfer, O-H center dot center dot center dot N) using N 1s XPS spectroscopy. The intermediate states of proton transfer arise when the pK(a) difference between the acid and the conjugate base is between -1 and 4, -1 < Delta pK(a) < 4, a situation common with COOH and pyridine functional groups present in drug molecules and pharmaceutically acceptable coformers. Complexes of pyridine N bases with aromatic COOH molecules in nine salts/cocrystals were cocrystallized, and their N 1s core binding energies in XPS spectra were measured. The proton state was analyzed by single-crystal X-ray diffraction for confirmation. Three new complexes were crystallized and analyzed by XPS spectra (without knowledge of their X-ray structures), to assess the predictive ability of XPS spectra in differentiating salt-cocrystal intermediate states against the extremities. The XPS results were subsequently confirmed by single-crystal X-ray data. Complexes of 3,5-dinitrobenzoic acid and isonicotinamide in 1:1 and 1:2 ratios exist as a salt and a salt-cocrystal continuum, respectively, as shown by the N 1s core binding energies. The proton states of the crystalline solids by XPS are in good agreement with the corresponding crystal structures. Other complexes, such as those of 3,5-dinitrobenzoic acid with 1,2-bis(4-pyridyl)ethylene, exhibit a salt-cocrystal continuum, maleic acids with 1,2-bis(4-pyridyl)ethylene and acridine are salts, 2-hydroxybenzoic acid and acridine is a salt, and the complex of 3,5-dinitrobenzoic acid and 3-hydroxypyridine is a salt and salt-cocrystal continuum, while fumaric acids with 1,2-bis(4-pyridyl)ethylene and acridine are cocrystals. Furthermore, three new acidbase complexes of 3,5-dinitrobenzoic acid with phenazine, 4-hydroxypyridine, and 4-cyanopyridine were studied initially by XPS and then confirmed by X-ray diffraction. In summary, since the N 1s binding energies cluster in a narrow range as cocrystals (398.7-398.9 eV) and salts (400.1-401.1 eV), it is clearly possible to differentiate between cocrystals and salts, but the saltcocrystal continuum values in XPS spectra are clustered in an intermediate range of cocrystals and salts but overlap with those of cocrystal or salt binding energies.

1 aTothadi, Srinu1 aShaikh, Tabrez, Rafique1 aGupta, Sharad1 aDandela, Rambabu1 aVinod, Chathakudath, P.1 aNangia, Ashwini, K. uhttp://library.ncl.res.in/content/can-we-identify-salt-cocrystal-continuum-state-using-xps01587nas a2200229 4500008004100000022001400041245016600055210006900221260000800290300001100298490000800309520073100317653002201048653003001070653003801100653002101138653002001159100001701179700001801196700001801214856012501232 2021 eng d a2468-823100aRole of metal-support interaction for atmospheric pressure CO2 hydrogenation over Pd/(Ti)-SBA-15 catalyst: effect of titanium composition on products selectivity0 aRole of metalsupport interaction for atmospheric pressure CO2 hy cJUL a1117320 v5113 aThe potential role of metal-support interaction for tuning the product selectivity during atmospheric pressure CO2 hydrogenation has been demonstrated on Pd/(Ti)-SBA-15 catalyst. Highly dispersed Pd NPs on SBA-15 (Pd/ SBA-15) was synthesized and further modified with titanium of varying composition. Comparison of catalytic activity of Pd/Ti-SBA-15 with its counterparts (Pd/SBA-15 and Pd/TiO2) illustrated the significance of strong PdTi interface in this catalyst and its role in tuning the product selectivity of CO2 hydrogenation. The generation of an ample amount of oxygen vacancies in the Pd/Ti-SBA-15 catalyst with maximum metallic Pd sites in close vicinity of Ti is proposed to boost the CO2 hydrogenation activity.10aCO2 hydrogenation10aMetal-support interaction10aModified deposition precipitation10aoxygen vacancies10aTitanosilicates1 aSoni, Yogita1 aGupta, Sharad1 aVinod, C., P. uhttp://library.ncl.res.in/content/role-metal-support-interaction-atmospheric-pressure-co2-hydrogenation-over-pdti-sba-1501888nas a2200181 4500008004100000022001400041245011200055210006900167260000800236300001600244490000800260520123600268100001801504700001701522700002301539700001801562856012601580 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. uhttp://library.ncl.res.in/content/morphology-dependent-catalysis-co3o4-nanostructures-atmospheric-pressure-carbon-dioxide