01431nas a2200193   4500008004100000022001500041245012700056210006900183260000800252300001600260490000700276520071800283100001801001700002501019700002601044700002701070700001601097856012401113       2018                        eng d  a 1463-907600aDissociative chemisorption of hydrogen molecules on defective graphene-supported aluminium clusters: a computational study0 aDissociative chemisorption of hydrogen molecules on defective gr  cNOV  a26506-265120 v203 a<p>Using periodic density functional theory-based calculations, in the present study, we address the chemical bonding between aluminium clusters (Al-n, n = 4-8 and 13) and monovacant defective graphene. The adsorption strength of the above-mentioned aluminium clusters is fivefold (approximate to 3 to 5 eV) higher on defective graphene as compared to the earlier reported values on non-defective graphene and BN-doped graphene. The Bader charge analysis and different charge densities reveal that this adsorption is driven by significant charge transfer from the Al clusters to defective graphene. Thus, chemisorbed Al clusters demonstrate high activity towards dissociative adsorption of molecular hydrogen.</p>1 aKumar, Deepak1 aGovindaraja, Thillai1 aKrishnamurty, Sailaja1 aKaliaperumal, Selvaraj1 aPal, Sourav  uhttps://library.ncl.res.in/content/dissociative-chemisorption-hydrogen-molecules-defective-graphene-supported-aluminium02277nas a2200253   4500008004100000022001400041245010300055210006900158260000900227300001100236490000900247520140000256653002301656653001601679653001901695653001601714653004201730653002101772100002901793700001701822700002701839700002601866856013101892       2019                        eng d  a2210-271X00aProbing the catalytic activity of pristine and doped Pd and Ni metal clusters towards H2O molecule0 aProbing the catalytic activity of pristine and doped Pd and Ni m  cDEC   a1126240 v11703 a<p>Electrolysis of H2O to produce molecular hydrogen, the most environment friendly and energy efficient fuel, using cost effective catalysts is one of the major global research challenges. To date, Pt remains the best suitable and yet highly expensive electro-catalyst for hydrogen evolution reaction. Design of an alternative cost-effective catalyst requires a fundamental molecular level understanding of the water molecule adsorption and its activation. In that context, we examine the adsorption and activation of water molecule on model alternative catalysts namely, Ni-6 and Pd-6 clusters using density functional theory based methodology. Ni-6 and Pd-6 clusters and their singly doped counterparts are used for this study. Mo, W, Fe, Co and Cu are used as doping elements. To quantify the influence of medium (neutral and alkaline) on the activation of the water molecule, Ni based clusters are considered in neutral and anionic states, respectively. The activity of these clusters towards H2O molecule is evaluated in terms of the adsorption energy, charge transfer, bandgap, red shift in O-H stretching frequency and dissociation barriers for H2O. The studies demonstrate that doping with Co in all the studied clusters (Pd-6, Ni-6 and anionic Ni-6) increases their activity. Best activity is noted for Fe doped neutral Ni b clusters with a dissociation barrier of 5.76 kcal/mol.</p>
10aActivation barrier10aNi clusters10aO-H activation10aPd clusters10aRed shift of O-H stretching frequency10aWater adsorption1 aSamal, Pragnya, Paramita1 aJoshi, Krati1 aKaliaperumal, Selvaraj1 aKrishnamurty, Sailaja  uhttps://library.ncl.res.in/content/probing-catalytic-activity-pristine-and-doped-pd-and-ni-metal-clusters-towards-h2o-molecule02265nas a2200169   4500008004100000022001400041245018100055210006900236260000900305300001400314490000700328520153700335100004301872700002601915700002701941856012701968       2021                        eng d  a1144-054600aGraphene-based frustrated Lewis pairs as bifunctional catalysts for CO2 reduction via the dissociative chemisorption of molecular H-2: a periodic density functional perspective0 aGraphenebased frustrated Lewis pairs as bifunctional catalysts f  cJUN   a9959-99660 v453 a<p>Nanocarbon-based frustrated Lewis pair (FLP) bifunctional catalysts, on account of their unquenched electron transfer property, are becoming increasingly attractive as catalysts for the CO2 reduction reaction via the dissociative chemisorption of H-2. In the present study, we propose a nanocarbon-based FLP catalyst. The pair comprises nitrogen doped/phosphorus doped graphene as Lewis bases and M(C6F5)(3) (M = B, Al, Ga, and In) as Lewis acids. The computational investigation reveals that the carbon atoms adjacent to the doped N and P atoms are the active sites towards the dissociative chemisorption of hydrogen molecule. The analyses of the Bader charges and difference charge densities validate the dissociative chemisorption of H-2 molecule and the fact that a significant electron redistribution promotes the polarization of the hydrogen molecule. Density of states confirms the hybridization between the p-states of the nitrogen/phosphorus atom and the s-state of hydrogen atom in all FLPs. The dissociative chemisorption of hydrogen is noted in all FLP complexes, thereby facilitating a low barrier reaction path for CO2 reduction. Between P-doped and N-doped FLPs, N-doped FLP catalysts prove to be a more promising counterpart with considerably low activation barriers, ranging between 0.01 and 0.11 eV, towards CO2 reduction. Thus, the present study demonstrates the great potential of doped carbon-based FLPs as novel nanostructure catalysts for CO2 reduction via the direct utilization of molecular hydrogen.</p>1 aSenthamaraikannan, Thillai, Govindaraj1 aKrishnamurty, Sailaja1 aKaliaperumal, Selvaraj  uhttps://library.ncl.res.in/content/graphene-based-frustrated-lewis-pairs-bifunctional-catalysts-co2-reduction-dissociative01934nas a2200157   4500008004100000022001400041245013800055210006900193260000800262490000600270520127200276100004301548700002701591700002601618856013201644       2021                        eng d  a2296-264600aRole of chemical structure of support in enhancing the catalytic activity of a single atom catalyst toward NRR: a computational study0 aRole of chemical structure of support in enhancing the catalytic  cSEP0 v93 aUsing the periodic density functional theory–based methodology, we propose a potential catalytic system for dinitrogen activation, viz., single metal atoms (Mo, Fe, and V) supported on graphene-based sheets. Graphene-based sheets show an excellent potential toward the anchoring of single atoms on them (Mo, Fe, and V) with adsorption energies ranging between 1.048 and 10.893 eV. Factors such as defects and BN doping are noted to enhance the adsorption energies of single metal atoms on the support. The adsorption of a dinitrogen molecule on metal atom–anchored graphene-based supports is seen to be highly favorable, ranging between 0.620 and 2.278 eV. The adsorption is driven through a direct hybridization between the d orbitals of the metal atom (Mo, Fe, and V) on the support and the p orbital of the molecular nitrogen. Noticeably, BN-doped graphene supporting a single metal atom (Mo, Fe, and V) activates the N<sub>2</sub> molecule with a red shift in the N–N stretching frequency (1,597 cm<sup>−1</sup> as compared to 2,330 cm<sup>−1</sup> in the free N<sub>2</sub> molecule). This red shift is corroborated by an increase in the N–N bond length (1.23 Å from 1.09 Å) and charge transfer to an N<sub>2</sub> molecule from the catalyst.1 aSenthamaraikannan, Thillai, Govindaraj1 aKaliaperumal, Selvaraj1 aKrishnamurty, Sailaja  uhttps://library.ncl.res.in/content/role-chemical-structure-support-enhancing-catalytic-activity-single-atom-catalyst-toward-nrr01687nas a2200253   4500008004100000022001400041245014600055210006900201260000800270300001200278490000700290520080300297653001901100653001501119653002401134653001601158653002501174653002801199100001801227700002701245700001601272700002601288856011901314       2023                        eng d  a2159-685900aUnleashing methylammonium-guanidinium lead iodide hybrid perovskite spherulitic microstructures: a structural and morphological investigation0 aUnleashing methylammoniumguanidinium lead iodide hybrid perovski  cJUN  a406-4150 v133 a<p>
	Perovskites can offer an attractive replacement option for existing commercial solar technologies. Herein microstructure plays an important role in improving the efficiency and stability of solar cells. Previously unidentified spherulitic microstructures of self-assembled polycrystalline perovskites are explored in this report. For this an intermediate phase of a promising guanidinium (GUAI)-rich perovskite has been investigated for its structural and morphological properties. This study infuses new insight into the evolution of perovskite microstructure from heterogeneity to homogeneity, as a result unravels the structure of perovskite embryonic spherulites, lamellar arrangements, transcrystalline nature, novel spherulites bridging, hole nucleation, impingement, and defects.</p>
10aMicrostructure10aMorphology10aNucleation & growth10aPerovskites10aPhase transformation10aX-ray diffraction (XRD)1 aMukul, Monika1 aKaliaperumal, Selvaraj1 aRani, Mamta1 aTripathi, Surya, Kant  uhttps://library.ncl.res.in/content/unleashing-methylammonium-guanidinium-lead-iodide-hybrid-perovskite-spherulitic