01991nas a2200265 4500008004100000022001400041245012300055210006900178260000900247300001400256490000700270520109400277653004101371653002101412653001601433653000801449653002001457100001601477700001101493700002801504700002001532700002401552700001801576856013101594 2019 eng d a1867-388000aCubic palladium nanorattles with solid octahedron gold core for catalysis and alkaline membrane fuel cell applications0 aCubic palladium nanorattles with solid octahedron gold core for  cSEP  a4383-43920 v113 a

Herein, we report the synthesis of palladium nanorattles (Au-Pd NRTs) comprising of a gold octahedral core caged within a thin porous cubic palladium shell. The introduction of core-shell and porous architecture was realized by combining seed mediated and galvanic replacement reaction techniques. Next, we examined the catalytic efficiency of the nanocatalyst in comparison with solid palladium nanocube (Pd-NC) of similar size for the degradation of p-nitrophenol and organic dyes. The rate constant of Au-Pd NRTs was found nearly 12 times higher than the Pd-NCs. Further, we exploited our catalyst for electrochemical oxygen reduction reaction (ORR) and observed its high intrinsic ORR activity. Compared with commercialized Pt/C, the Au-Pd NRT displayed nearly comparable onset and half-wave potential values and excellent durability upon potential cycling. The system level validation in a single-cell mode of alkaline exchange membrane fuel cell also confirms the efficiency of the present catalyst to serve as a potential cathode catalyst for realistic device applications.

10aalkaline exchange membrane fuel cell10aelectrocatalysis10ananorattles10aORR10aPd nanoparticle1 aSingh, Prem1 aSonika1 aGangadharan, Pranav, K.1 aKhan, Ziyauddin1 aKurungot, Sreekumar1 aJaiswal, Amit uhttps://library.ncl.res.in/content/cubic-palladium-nanorattles-solid-octahedron-gold-core-catalysis-and-alkaline-membrane-fuel01677nas a2200301 4500008004100000022001400041245015300055210006900208260001000277300001100287490000800298520065100306653001400957653002700971653001700998653000801015100002501023700002701048700001301075700002001088700002201108700002401130700003001154700002401184700002101208700002001229856012601249 2020 eng d a0167-577X00aFe3+ stabilized 3D cross-linked glycine-melamine formaldehyde networks as precursor for highly efficient oxygen reduction catalyst in alkaline media0 aFe3 stabilized 3D crosslinked glycinemelamine formaldehyde netwo cAPR 1 a1273650 v2643 a

Development of inexpensive oxygen reduction electrocatalyst with high activity and durability is very important. Herein, iron carbide encapsulated pod-like graphitic carbon structures were prepared by simple pyrolysis involving Fe-glycine complex integrated melamine-formaldehyde resin precursor. The best catalyst among those studied, Fe-Gly 2 MF-C, possessing high degree of graphitization (I-D /I-G = 0.99) and enhanced specific surface area (205 m(2)/g) exhibited the highest ORR activity with a half-wave potential of 0.80 V in alkaline medium through the four-electron reduction pathway. (C) 2020 Elsevier B.V. All rights reserved.

10afuel cell10aGraphitic carbon alloy10aIron carbide10aORR1 aKottarathil, Shijina1 aIllathvalappil, Rajith1 aNisa, S.1 aSailaja, G., S.1 aMohamed, Peer, A.1 aNair, Balagopal, N.1 aGopinathan, Anilkumar, M.1 aKurungot, Sreekumar1 aYamaguchi, Takeo1 aHareesh, U., S. uhttps://library.ncl.res.in/content/fe3-stabilized-3d-cross-linked-glycine-melamine-formaldehyde-networks-precursor-highly02015nas a2200217 4500008004100000022001400041245012400055210006900179260000800248300001200256490000700268520127400275653000901549653002201558653000801580653001301588100002201601700002401623700001801647856013201665 2021 eng d a1944-824400aEfficient electrochemical oxygen reduction to hydrogen peroxide by transition metal-doped silicate Sr0.7Na0.3SiO3-delta0 aEfficient electrochemical oxygen reduction to hydrogen peroxide  cJAN a382-3900 v133 a

Electrochemical oxygen reduction in a selective two-electron pathway is an efficient method for onsite production of H2O2. State of the art noble metal-based catalysts will be prohibitive for widespread applications, and hence earth-abundant oxide-based systems are most desired. Here we report transition metal (Mn, Fe, Ni, Cu)-doped silicates, Sr0.7Na0.3SiO3-delta, as potential electrocatalysts for oxygen reduction to H2O2 in alkaline conditions. These novel compounds are isostructural with the parent Sr0.7Na0.3SiO3-delta and crystallize in monoclinic structure with corner-shared SiO4 groups forming cyclic trimers. The presence of Na stabilizes O vacancies created on doping, and the transition metal ions provide catalytically active sites. Electrochemical parameters estimated from Tafel and Koutechy-Levich plots suggest a two-electron transfer mechanism, indicating peroxide formation. This is confirmed by the rotating ring disc electrode method, and peroxide selectivity and Faradaic efficiency are calculated to be in the range of 65-82% and 50-68%, respectively, in a potential window 0.3 to 0.6 V (vs RHE). Of all the dopants, Ni imparts the maximum selectivity and efficiency as well as highest rate of formation of H2O2 at 1.65 mu mol s(-1).

10aH2O210amixed metal oxide10aORR10asilicate1 aThundiyil, Shibin1 aKurungot, Sreekumar1 aDevi, Nandini uhttps://library.ncl.res.in/content/efficient-electrochemical-oxygen-reduction-hydrogen-peroxide-transition-metal-doped-silicate02306nas a2200313 4500008004100000022001400041245012200055210006900177260000900246300001200255490000800267520128400275653000801559653000801567653000801575653001001583653005201593100001801645700001901663700002801682700002201710700001701732700002001749700002301769700002401792700002201816700002301838856013101861 2021 eng d a0021-979700aEnhanced electrocatalytic activity of PtRu/nitrogen and sulphur co-doped crumbled graphene in acid and alkaline media0 aEnhanced electrocatalytic activity of PtRunitrogen and sulphur c cMAY  a154-1630 v5903 a

The low mass activity and high price of pure platinum (Pt)-based catalysts predominantly limit their large-scale utilization in electrocatalysis. Therefore, the reduction of Pt amount while preserving the electrocatalytic efficiency represents a viable alternative. In this work, we prepared new PtRu2 nanoparticles supported on sulphur and nitrogen co-doped crumbled graphene with trace amounts of iron (PtRu2/PF) electrocatalysts. The PtRu2/PF catalysts exhibited enhanced electrocatalytic performance and stability for the hydrogen evolution reaction (HER) at pH = 0. Moreover, the prepared PtRu2/PF electrocatalyst displayed higher HER activity than commercial 20% Pt/C. The PtRu2/PF catalyst achieved a current density of 10 mA cm(-2) at an overpotential value of only 22 mV for HER, performing better activity than many other Pt-based electrocatalysts. Besides, the PtRu2/PF revealed a good performance for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline media. The PtRu2/PF catalyst recorded a current density of 10 mA cm(-2) at an overpotential of only 270 mV for OER in KOH (1.0 M) solution and an onset potential of 0.96 V vs. RHE (at 1 mA cm(-2)) for ORR in KOH (0.1 M) solution. (C) 2021 Elsevier Inc. All rights reserved.

10aHER10aOER10aORR10aPtRu210aSulphur and nitrogen co-doped crumbled graphene1 aPang, Liuqing1 aMiao, Yuanyuan1 aBhange, Siddheshwar, N.1 aBarras, Alexandre1 aAddad, Ahmed1 aRoussel, Pascal1 aAmin, Mohammed, A.1 aKurungot, Sreekumar1 aSzunerits, Sabine1 aBoukherroub, Rabah uhttps://library.ncl.res.in/content/enhanced-electrocatalytic-activity-ptrunitrogen-and-sulphur-co-doped-crumbled-graphene-acid03106nas a2200241 4500008004100000022001400041245014800055210006900203260000900272300001600281490000700297520225700304653002402561653003102585653000802616653001002624653002102634653001602655100002102671700001802692700002402710856013002734 2023 eng d a1944-824400aMicroporous 3D-structured hierarchically entangled graphene-supported Pt3Co alloy catalyst for PEMFC application with process-friendly features0 aMicroporous 3Dstructured hierarchically entangled graphenesuppor cJUN  a28023-280350 v153 a

To improve the oxygen reduction reaction(ORR) performance in aproton-exchange membrane fuel cell (PEMFC) cathode with respect tomass activity and durability, a suitable electrocatalyst design strategyis essentially needed. Here, we have prepared a sub-three nm-sizedplatinum (Pt)-cobalt (Co) alloy (Pt3Co)-supportedN-doped microporous 3D graphene (Pt3Co/pNEGF) by usingthe polyol synthesis method. A microwave-assisted synthesis methodwas employed to prepare the catalyst based on the 3D porous carbonsupport with a large pore volume and dense micro-/mesoporous surfaces.The ORR performance of Pt3Co/pNEGF closely matches withthe state-of-the-art commercial Pt/C catalyst in0.1 M HClO4, with a small overpotential of 10 mV. The 3Dmicroporous structure of the N-doped graphene significantly improvesthe mass transport of the reactant and thus the overall ORR performance.As a result of the lower loading of Pt in Pt3Co/pNEGF ascompared to that in Pt/C, the alloy catalyst achieved 1.5 times highermass activity than Pt/C. After 10,000 cycles, the difference in theelectrochemically active surface area (ECSA) and half-wave potential(E (1/2)) of Pt3Co/pNEGF is foundto be 5 m(2) g(Pt) (-1) (Delta ECSA)and 24 mV (Delta E (1/2)), whereas, forPt/C, these values are 9 m(2) g(Pt) (-1) and 32 mV, respectively. Finally, in a realistic perspective, single-celltesting of a membrane electrode assembly (MEA) was made by sandwichingthe Pt3Co/pNEGF-coated gas diffusion layers as the cathodedisplayed a maximum power density of 800 mW cm(-2) under H-2-O-2 feed conditions with aclear indication of helping the system in the mass-transfer region(i.e., the high current dragging condition). The nature of the I-V polarization shows a progressivelylower slope in this region of the polarization plot compared to asimilar system made from its Pt/C counterpart and a significantlyimproved performance throughout the polarization region in the caseof the system made from the Pt3Co/NEGF catalyst (withoutthe microwave treatment) counterpart. These results validate the betterprocess friendliness of Pt3Co/pNEGF as a PEMFC electrode-specificcatalyst owing to its unique texture with 3D architecture and well-definedporosity with better structural endurance.

10amicrowave synthesis10aN-doped porous 3D graphene10aORR10aPEMFC10apolyol synthesis10aPt3Co alloy1 aManna, Narugopal1 aSingh, Mayank1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/microporous-3d-structured-hierarchically-entangled-graphene-supported-pt3co-alloy-catalyst