01940nas a2200241 4500008004100000022001400041245011400055210006900169260005700238300000900295490000800304520105600312653002401368653003601392653001101428653002401439653002101463100002101484700002201505700002601527700001601553856012901569 2014 eng d a1432-881X00aComputational investigation on the catalytic activity of Rh-6 and Rh4Ru2 clusters towards methanol activation0 aComputational investigation on the catalytic activity of Rh6 and a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcDEC a15970 v1343 a

Catalysis of molecular activation of small molecules through scission of strong chemical bonds is one of the major challenges faced by chemists. More specifically, activation of the strong C-H and O-H bonds of various alcohols, especially methanol, is one of the various important intermediate steps of key organic reactions. Our present work explores a suitable metal cluster catalyst towards methanol dissociation. In particular, we have examined the effect of ruthenium doping (Rh:Ru = 2:1) on the catalytic activity of Rh-6 cluster towards methanol dissociation. Density functional theory-based calculations illustrate two competitive pathways for methanol dissociation, which are via O-H and C-H bond breaking. Both the pathways are found to be energetically favourable in the presence of bimetallic and mono-metallic clusters. Importantly, energy barrier for O-H bond dissociation reduces considerably in doped cluster as compared to pure Rh-6 cluster and is smaller than the values reported for a number of other small metallic clusters.

10aBimetallic Clusters10aDensity Functional Theory (DFT)10aDoping10aMethanol Activation10aRhodium Clusters1 aGhatak, Kamalika1 aSengupta, Turbasu1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/computational-investigation-catalytic-activity-rh-6-and-rh4ru2-clusters-towards-methanol-001929nas a2200157 4500008004100000245016500041210006900206260000800275300001600283490000800299520127400307100001701581700002601598700001601624856013101640 2016 eng d00aContriving a catalytically active structure from an inert conformation: a density functionalinvestigation of Al, Hf, and Ge doping of Au-20 tetrahedral clusters0 aContriving a catalytically active structure from an inert confor cSEP a19636-196410 v1203 a

The transformation of an inert structure into a catalytically active conformation has immense potential from a structural engineering point of view. In the present work, we explored methods of achieving such a transformation through a density-functional-based study. Au-20 is known be one of the most stable and catalytically inert gold clusters, with a well-known tetrahedral structure. We demonstrate the transformation of the inert Au-20 conformation into a highly active catalytic cluster through selective doping with Hf and Ge atoms. Depending on the dopant, the inert tetrahedral Au-20 cluster evolves into either an endohedral or a hollow-cage-like conformation. The structural changes are manifested in the catalytic properties as well, with the result that the transformed doped cages exhibit extremely low activation barriers for the environmentally important CO oxidation reaction as compared to reported inert Au-20 cluster. The activation barriers for CO oxidation are particularly low (<0.12 eV) when germanium is directly involved in the CO oxidation. Thus, the current work highlights the importance of engineering structural properties of metal nanoclusters with the help of heteroatom dopants for future applications in efficient catalysis.

1 aManzoor, Dar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttp://library.ncl.res.in/content/contriving-catalytically-active-structure-inert-conformation-density-functionalinvestigation02342nas a2200229 4500008004100000022001400041245011800055210006900173260000800242490000700250520149600257653002801753653001901781653002801800653002101828653003201849100002501881700002901906700002701935700002601962856012401988 2023 eng d a1439-423500aCan Li atoms anchored on boron- and nitrogen-doped graphene catalyze dinitrogen molecules to ammonia? a DFT study0 aCan Li atoms anchored on boron and nitrogendoped graphene cataly cJUN0 v243 a

The most successful electrochemical conversion of ammonia from dinitrogen molecule reported to date is through a Li mediated mechanism. In the framework of the above fact and that Li anchored graphene is an experimentally feasible system, the present work is a computational experiment to identify the potential of Li anchored graphene as a catalyst for N-2 to NH3 conversion as a function of (a) minimum number of Li atoms needed for anchoring on graphene sheets and (b) the role of chemical modification of graphene surfaces. The studies bring forth an understanding that Li anchored graphene sheets are potential catalysts for ammonia conversion with preferential adsorption of N-2 through end-on configuration on Li atoms anchored on doped and pristine graphene surfaces. This mode of adsorption being characteristic of Nitrogen Reduction Reaction (NRR) through enzymatic pathway, examination of the same followed by analysis of electronic properties demonstrates that tri-Li atoms (Tri Atom Catalysts, TACs) are more efficient as catalysts for NRR as compared to two Li atoms (Di Atom Catalysts, DACs). Either way, the rate determining step was found to be *NH2 ->*NH3 step (mixed pathway) with Delta G(max)=1.02 eV and *NH2-*NH3 ->*NH2 step (enzymatic pathway) with Delta G(max)=1.11 eV for 1B doped TAC and DAC on graphene sheet, respectively. Consequently, this work identifies the viability of Li anchored graphene based 2-D sheets as hetero-atom catalyst for NRR.

10acomputational chemistry10aGraphene Sheet10aheterogeneous catalysis10aLi Nanoparticles10aNitrogen Reduction Reaction1 aVerma, Tushar, Singh1 aSamal, Pragnya, Paramita1 aSelvaraj, Kaliaperumal1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/can-li-atoms-anchored-boron-and-nitrogen-doped-graphene-catalyze-dinitrogen-molecules01681nas a2200205 4500008004100000022001400041245011900055210006900174260000800243300001400251490000700265520092200272100002101194700002901215700002501244700002301269700002601292700002801318856012901346 2023 eng d a0022-326300aCatalyst-assisted selective vinylation and methylallylation of a quaternary carbon center using tert-butyl acetate0 aCatalystassisted selective vinylation and methylallylation of a  cJUL a9686-97030 v883 a

The In-(OTf)(3)-catalyzed & alpha;-vinylationof varioushydroxy-functionalized quaternary carbon centers using in situ generatedisobutylene from tert-butyl acetate is presentedas a novel synthetic methodology. Moreover, tert-butylacetate is a nonflammable feed stock and is a readily available sourcefor the in situ production of vinyl substituents, as demonstratedby the vinylation reaction with quaternary hydroxy/methoxy compounds.Moreover, an excellent selectivity for methylallylation over vinylationwas obtained with Ni-(OTf)(2) as a catalyst. In the case ofperoxyoxindole, methylallyl-functionalized 1,4-benzoxazin-3-one derivativeswere formed through the sequential rearrangement of peroxyoxindolefollowed by the nucleophilic attack by isobutylene. The detailed mechanismfor this reaction and rationalization for the selectivity are providedusing kinetics and density functional theory studies.

1 aMohanta, Nirmala1 aSamal, Pragnya, Paramita1 aPandey, Akanksha, M.1 aMondal, Shankhajit1 aKrishnamurty, Sailaja1 aGnanaprakasam, Boopathy uhttp://library.ncl.res.in/content/catalyst-assisted-selective-vinylation-and-methylallylation-quaternary-carbon-center-using02387nas a2200301 4500008004100000022001400041245012100055210006900176260000800245300001600253490000700269520134900276653002001625653002001645653002901665653003601694653002701730653003201757100001901789700002201808700002401830700002601854700001901880700002601899700001901925700001601944856012501960 2023 eng d a1944-824400aChemical bridge-mediated heterojunction electron transport layers enable efficient and stable perovskite solar cells0 aChemical bridgemediated heterojunction electron transport layers cJUN a29597-296080 v153 a

Perovskite solar cells (PSCs) emerged as potential photovoltaicenergy-generating devices developing in recent years because of theirexcellent photovoltaic properties and ease of processing. However,PSCs are still reporting efficiencies much lower than their theoreticallimits owing to various losses caused by the charge transport layerand the perovskite. In this regard, herein, an interface engineeringstrategy using functional molecules and chemical bridges was appliedto reduce the loss of the heterojunction electron transport layer.As a functional interface layer, ethylenediaminetetraacetic acid (EDTA)was introduced between PCBM and the ZnO layer, and as a result, EDTAsimultaneously formed chemical bonds with PCBM and ZnO to serve asa chemical bridge connecting the two. DFT and chemical analyses revealedthat EDTA can act as a chemical bridge between PCBM and ZnO, passivatedefect sites, and improve charge transfer. Optoelectrical analysisproved that EDTA chemical bridge-mediated charge transfer (CBM-CT)provides more efficient interfacial charge transport by reducing trap-assistedrecombination losses at ETL interfaces, thereby improving device performance.The PSC with EDTA chemical bridge-mediated heterojunction ETL exhibiteda high PCE of 21.21%, almost no hysteresis, and excellent stabilityto both air and light.

10acharge transfer10achemical bridge10aelectron transport layer10aethylenediaminetetraacetic acid10aPerovskite solar cells10atrap-assisted recombination1 aPatil, Pramila1 aMaibam, Ashakiran1 aSangale, Sushil, S.1 aMann, Dilpreet, Singh1 aLee, Hyun-Jung1 aKrishnamurty, Sailaja1 aKwon, Sung-Nam1 aNa, Seok-In uhttp://library.ncl.res.in/content/chemical-bridge-mediated-heterojunction-electron-transport-layers-enable-efficient-and02218nas a2200229 4500008004100000022001400041245011500055210006900170260000800239300001100247490000800258520137100266653001501637653003101652653003001683653003001713653003101743100002701774700003001801700002601831856013101857 2023 eng d a0169-433200aChemically modified graphene sheets as potential sensors for organophosphate compounds(pesticide): A DFT study0 aChemically modified graphene sheets as potential sensors for org cMAY a1567450 v6193 a

Owing to the extensive use of pesticides in agriculture and the threat posed to the environment and humankind, attention is drawn toward the need for its remediation from various sources, in particular from water. The adsorption characteristics of hydrophobic graphene and its BN doped counterparts are evaluated using DFT methodology, to assess their sensing potential towards notable pesticide molecules (Organophosphate pesticides (OPs) such as chlorpyriphos, parathion, methyl-parathion, and fenitrothion). To accomplish this, various elec-tronic properties such as band structure, DOS, Bader charge analysis, and CDD have been calculated. Interest-ingly, exothermic interactions (-0.1 eV to-2 eV) have been noted for all the OPs with NB doped single vacancy defect induced graphene surfaces. With an exception of FTN, all the other OPs showed significant changes in the electronic properties of surfaces as apparent from the change in band gap and nature of the band from indirect to direct. The appreciable adsorption energy, higher charge transfer, and notable variation in the band gap are the decisive factors behind the strong interaction exhibited by NB doped surfaces especially dg-(NB-2)2 (except FTN). These findings demonstrate the suitability of NB doped single vacancy defect induced graphene sheets for the detection of the studied OPs.

10aAdsorption10aBN doped graphene surfaces10aCharge density difference10aDensity functional theory10aOrganophosphate pesticides1 aShivankar, Bhavana, R.1 aSingh, Chandrodai, Pratap1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/chemically-modified-graphene-sheets-potential-sensors-organophosphate-compoundspesticide-dft02051nas a2200265 4500008004100000022001400041245015000055210006900205260000900274300001400283490000700297520102600304653002401330653003601354653005501390653003801445653003001483653002001513100002501533700002501558700002401583700002701607700002601634856012501660 2024 eng d a0360-319900aComputational identification of most potent atom pair catalysts for electrocatalytic nitrogen reduction reaction over hydrogen evolution reaction0 aComputational identification of most potent atom pair catalysts  cMAR  a1345-13580 v583 a

Robust electrocatalytic atom pair compositions (APCs) where Nitrogen Reduction Reaction (NRR) is more enhanced over competing Hydrogen Evolution Reaction (HER) is searched for using computational studies based on Density Functional Theory based methods. Atomic pairs are anchored on mechanically and thermally stable graphene surfaces. A wide range of transition metal based atom pair compositions from 3d, 4d, and 5d groups are systematically investigated for reduction of dinitrogen molecule with lower reduction barrier as compared to HER. APR compositions of Ni-Rh with an overall limiting potential of -0.22 V, Fe-W with an overall limiting potential of -0.26 V and Co-Pt with an overall limiting potential of -0.28 V are identified as the most potent atomic pairs for enhanced nitrogen reduction reaction over the HER. Finally, the performance of most potent composition, viz., Ni-Rh is validated to be consistent with respect to their thermodynamic stability and performance within the solvent effects.

10aAtom pair catalysts10aDensity Functional Theory (DFT)10aElectrochemical nitrogen reduction reaction (eNRR)10ahydrogen evolution reaction (HER)10aIR stretching frequencies10aN-N bond length1 aVerma, Tushar, Singh1 aDar, Afshana, Hassan1 aDar, Manzoor, Ahmad1 aSelvaraj, Kaliaperumal1 aKrishnamurty, Sailaja uhttp://library.ncl.res.in/content/computational-identification-most-potent-atom-pair-catalysts-electrocatalytic-nitrogen