02844nas a2200241 4500008004100000022001400041245017400055210006900229260000800298300001400306490000600320520196200326653001602288653002002304653001402324653003002338653001902368100001802387700002802405700001502433700002402448856013002472 2020 eng d a2574-096200aWO3 nanorods bearing interconnected Pt nanoparticle units as an activity-modulated and corrosion-resistant carbon-free system for polymer electrolyte membrane fuel cells0 aWO3 nanorods bearing interconnected Pt nanoparticle units as an  cFEB a1908-19210 v33 a

Commercial platinum-supported carbon (Pt/C) catalyst is the most widely used oxygen reduction reaction (ORR) electrocatalyst in polymer electrolyte membrane fuel cells (PEMFCs). However, carbon oxidation in Pt/C during the operation of PEMFCs poses serious issues, particularly in meeting long-term durability of the cells. Although carbon-free Pt-based catalysts are considered to be the best alternatives, the single-cell performances reported for many such systems are found to be inferior to that of the carbon-based systems. As a practical way to realize a carbon-free electrocatalyst, we have developed a system by dispersing an interconnected Pt nanoparticle network on the nanorods of tungsten oxide (WO3). Uniform dispersion of the WO3 nanorods by fine and more or less interconnected Pt nanoparticles (20 wt %) is a key feature of the electrocatalyst. This has helped the system to achieve an intrinsic ORR characteristics which is very similar to that of Pt/C, as reflected from the comparative analysis of the onset potential, half-wave potential, limiting current density, and the number of electrons transferred in the ORR process. Pt/WO3 also shows better stability under start-stop accelerated potential cycling after 10 000 cycles, compared to Pt/C. The relative decrement in the electrochemically active surface area (ECSA) for Pt/WO3 nanorods was negligible, compared to the similar to 26% decrement registered by Pt/C under the identical testing conditions. Finally, a system-level validation in a single-cell model of PEMFC by fabricating a membrane electrode assembly (MEA) with Pt/WO3 as both the anode and cathode catalyst delivered comparable output power density as that of a similar system fabricated by using Pt/C. ECSA comparison in MEA shows the potential use of Pt/WO3-400 as the catalyst for the fuel cells, since it is exhibiting an ECSA value that is 3.4 greater than that of Pt/C at a Pt loading of 0.5 mg cm(-2).

10aCarbon-free10aelectrocatalyst10afuel cell10aoxygen reduction reaction10atungsten oxide1 aKumar, Sachin1 aBhange, Siddheshwar, N.1 aSoni, Roby1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/wo3-nanorods-bearing-interconnected-pt-nanoparticle-units-activity-modulated-and-corrosion02131nas a2200169 4500008004100000022001400041245010800055210006900163260000800232300001400240490000600254520151300260100001801773700001501791700002401806856013101830 2021 eng d a2398-490200aPdP/WO3 multi-functional catalyst with high activity and stability for direct liquid fuel cells (DLFCs)0 aPdPWO3 multifunctional catalyst with high activity and stability cSEP a4758-47700 v53 aDirect liquid fuel cells are energy conversion devices which utilize formate and methanol as fuels. These systems are relieved of the problem of H-2 transport and storage, making them highly desirable for various practical applications. However, the low stability and activity of carbon supported catalysts such as Pt/C both in the anode and cathode is a critical hindering factor towards their further development. As a practical solution to overcome this issue, in this work, we report on the development of phosphorus-doped palladium (PdP) nanoparticle-supported tungsten oxide (WO3) nanorods (PdP/WO3) as a versatile multifunctional catalyst for facilitating the oxidation of formate and methanol in the anode and the oxygen reduction reaction (ORR) in the cathode. Strong metal-support interactions and electronic modifications incurred by the doped phosphorus help this system to achieve desirable properties to enable it to effectively function both for the anode and cathode applications. PdP/WO3 showed 16-times higher mass activity compared to Pt/C even after 3000 start/stop cycles for the ORR. For formate and methanol oxidation, PdP/WO3 exhibited current densities of 0.50 and 0.734 A mg(Pd)(-1), respectively, outperforming the state-of-the-art catalysts. With these bifunctional features, PdP/WO3 stands out as a potential system to be used as an anode and cathode catalyst in direct liquid fuel cells, all the while offering an opportunity for the development of carbon-free electrocatalysts.1 aKumar, Sachin1 aSoni, Roby1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/pdpwo3-multi-functional-catalyst-high-activity-and-stability-direct-liquid-fuel-cells-dlfcs02156nas a2200229 4500008004100000022001400041245014800055210006900203260000800272490000600280520131300286653003301599653001501632653003001647653002401677100001801701700002001719700002401739700001501763700002401778856012401802 2023 eng d a2366-748600aPt-anchored-zirconium phosphate nanoplates as high-durable carbon-free oxygen reduction reaction electrocatalyst for PEM fuel cell applications0 aPtanchoredzirconium phosphate nanoplates as highdurable carbonfr cFEB0 v73 a

Commercially available platinum-supported carbon (Pt/C) catalysts are the most widely used oxygen reduction reaction (ORR) electrocatalysts in polymer electrolyte membrane fuel cells (PEMFCs). However, inadequate active triple-phase boundary formation and carbon oxidation in Pt/C during PEMFC operation shorten its lifetime and efficiency. In this direction, a new class of carbon-free electrocatalysts for ORR is prepared by dispersing Pt nanoparticles on ZrP (Zirconium phosphates) nanoplates. In one case (ZrP@Pt), the Pt nanoparticles are found to be closely distributed and completely covering the ZrP nanoplates, whereas in the second case (Pt/ZrP), the Pt nanoparticles selectively restrict dispersion along the edges of the support. ZrP as the support displays an intrinsic proton conductivity of approximate to 0.5 x 10(-4) S cm(-1) at 70 degrees C, with an activation energy (E-a) of 0.19 eV. Pt/ZrP shows better durability after 3000 start-stop cycles. The mass activity of Pt/ZrP is increased by 4.6 times compared to Pt/C, which exhibits a loss in mass activity by 1.37 times. The single-cell level validation of ZrP@Pt, Pt/ZrP, and Pt/C as the electrocatalysts in PEMFC at an operating potential of 0.60 V shows the achievable current densities of 0.600, 0.890, and 0.890 A cm(-2).

10acarbon-free electrocatalysts10afuel cells10aoxygen reduction reaction10azirconium phosphate1 aKumar, Sachin1 aYoyakki, Athira1 aPandikassala, Ajmal1 aSoni, Roby1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/pt-anchored-zirconium-phosphate-nanoplates-high-durable-carbon-free-oxygen-reduction02125nas a2200313 4500008004100000022001400041245008000055210006900135260000900204490000900213520118500222653000601407653001501413653002201428653002601450653001001476653001601486653000801502653002601510100001701536700001801553700002301571700001901594700001901613700002101632700002601653700002501679856010701704 2024 eng d a0022-286000a4-aminoantipyrine linked bis-1,2,3-triazole based probes for Cu(II) sensing0 a4aminoantipyrine linked bis123triazole based probes for CuII sen cFEB 0 v12973 a

Herein, two molecular probes of 4-aminoantipyrine-linked bis-1,2,3-triazoles have been studied for metal ion sensing applications. The crystal structure of one of the probes named as 4,4 `-((4,4 `-(((1,5-dimethyl- 3- oxo- 2- phenyl- 2,3- dihydro- 1H- pyrazol- 4-yl) azanediyl) bis(methylene))bis(1H-1,2,3-triazole-4,1-diyl))bis(methylene))dibenzonit rile (3b) crystalizes in Monoclinic crystal system in P 1 21/n 1 space group. Both probes responded more strongly and selectively to Cu(II) than other tested metal ions (K+, Na+, Mg2+, Ba2+, Ca2+, Cr3+, Mn2+, Co2+, Zn2+, Cd2+, Ni2+, Hg2+, and Pb2+). Job's plot suggested a 1:1 stoichiometric ratio of ligand and metal ion. Both probes showed an association constant of 2.48 x 10(3) M-1 and 3.73 x 10(3) M-1 through Benesi-Hildebrand (B-H) plot. The geometries of both probes and their complexes were optimized by DFT using B3LYP/6-311 G(d,p) and B3LYP/LanL2DZ basis sets, and properties were supported by Mulliken atomic charge and Molecular electrostatic potential. Molecular docking on both probes and their complexes with Type-II topoisomerases(PDB ID: 4G0V) protein was conducted to foretastes anticancer activity.

10a210a3-Triazole10a4-aminoantipyrine10aand Molecular docking10aBis-110aCu2+ Sensor10aDFT10aX-ray crystallography1 aLal, Bajrang1 aKumar, Sachin1 aTittal, Ram, Kumar1 aSingh, Gurleen1 aSingh, Jandeep1 aGhule, Vikas, D.1 aMathpati, Ramling, S.1 aSabane, Jagjivan, K. uhttps://library.ncl.res.in/content/4-aminoantipyrine-linked-bis-123-triazole-based-probes-cuii-sensing02936nas a2200301 4500008004100000022001400041245013700055210006900192260000800261490000700269520184900276653003702125653001802162653004202180653003002222653003002252653001702282100002002299700003002319700002902349700002502378700001802403700002002421700001802441700002602459700002402485856012502509 2024 eng d a1613-681000aBreaking the Pt electron symmetry and OH spillover towards ptir active center for performance modulation in direct ammonia fuel cell0 aBreaking the Pt electron symmetry and OH spillover towards ptir  cDEC0 v203 a

The growing interest in low-temperature direct ammonia fuel cells (DAFCs) arises from the utilization of a carbon-neutral ammonia source; however, DAFCs encounter significant electrode overpotentials due to the substantial energy barrier of the *NH2 to *NH dehydrogenation, compounded by the facile deactivation by *N on the Pt surface. In this work, a unique catalyst, Pt4Ir@AlOOH/NGr i.e., Pt4Ir/ANGr, is introduced composed of PtIr alloy nanoparticles controllably decorated on the pseudo-boehmite phase of AlOOH-supported nitrogen-doped reduced graphene (AlOOH/NGr) composite, synthesized via the polyol reduction method. The detailed studies on the structural and electronic properties of the catalyst by XAS and VB-XPS reveal the possible electronic modulations. The optimized Pt4Ir/ANGr composition exhibits a significantly improved onset potential and mass activity for AOR. The DFT study confirms the OHad species spillover by AlOOH and Pt4Ir (100) facilitates the conversion of the *NH2 to *NH with minimal energy barriers. Finally, testing of DAFC at the system level using a membrane electrode assembly (MEA) with Pt4Ir/ANGr as the anode catalyst, demonstrating the suitability of the catalyst for its practical applications. This study thus uncovers the potential of the Pt4Ir catalyst in synergy with ANGr, largely addressing the challenges in hydrogen transportation, storage, and safety within DAFCs. In this article, a versatile catalyst, Pt4Ir/ANGr, is introduced composed of PtIr alloy nanoparticles decorated on AlOOH/NGr composite. The AlOOH provides an -OH-rich surface conducive to the facile adsorption and decoration of the PtIr alloy nanoparticles and OHad species spillover from AlOOH to the Pt4Ir active center during AOR, further validating the higher experimental activity obtained in Pt4Ir/ANGr. image

10aammonia oxidation reaction (AOR)10ad-band center10adensity functional theory (DFT) study10adirect ammonia fuel cells10ahydroxyl spillover effect10aXAS analysis1 aBarik, Sidharth1 aKharabe, Geeta, Pandurang1 aSamal, Pragnya, Paramita1 aUrkude, Rajashri, R.1 aKumar, Sachin1 aYoyakki, Athira1 aVinod, C., P.1 aKrishnamurty, Sailaja1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/breaking-pt-electron-symmetry-and-oh-spillover-towards-ptir-active-center-performance05858nas a2200145 4500008004100000245014400041210006900185260000800254490000600262520525100268100001805519700002005537700002405557856013105581 2024 eng d00aSurface-anchored PtNi alloy network over SiO2 (PtNi/SiO2): a versatile carbon-free cathode for proton exchange membrane fuel cells (PEMFCs)0 aSurfaceanchored PtNi alloy network over SiO2 PtNiSiO2 a versatil cAPR0 v23 a

The large-scale commercialization of the PEMFCs is hindered due to the high cost of the Pt-based electrocatalysts (Pt/C) and the low durability associated with the oxidation of the carbon support in Pt/C. Many Pt-based carbon-free electrocatalysts have been explored, exhibiting excellent stability and activity, but the performance is further expected to be improved by developing suitable Pt alloy catalysts based on the carbon-free supports. To explore this possibility, we have developed a PtNi/SiO2 alloy system, which acts as a carbon-free electrocatalyst exhibiting enhanced activity for the oxygen reduction reaction (ORR). A half-cell study of PtNi/SiO2 (45 wt%) shows ∼4.3 times higher ORR activity compared to the state-of-the-art Pt/C (40%). The uniform distribution of the PtNi nanoparticles over SiO2 is the crucial feature of the catalyst. PtNi/SiO2 shows better durability even after 5000 cycles compared to the state-of-the-art Pt/C. The catalyst shows a negative shift in the half-wave potential (E1/2) by only 5 mV, which is lower than that of the 11 mV drop incurred by Pt/C. Considering this high activity of the PtNi/SiO2 catalyst for the ORR, we tried to explore the possibility of demonstrating a single-cell PEMFC in the MEA by pairing the catalyst as the cathode along with the Pt/C as the anode. This paired configuration of the single cell is found to be providing promising performance by delivering a current density of 960 mA/cm2 at 0.60 V and a maximum power density of 835 mW/cm2. Thus, this study outlines the possibility of developing potential alloy combinations of Pt on carbon-free substrates and then deploying them as electrodes for PEMFC applications. In the context of mitigating the carbon corrosion-related issues without compromising the intrinsic activities of the catalysts, the development of suitable alloy combinations on various carbon-free substrates is of significant technological advantages. The formation of the alloy phase along with the fine and uniform distribution of the alloy nanoparticles on the SiO2 substrate, followed by its successful deployment as the cathode of a single cell, points toward the scope of exploring material developments in this direction.

1 aKumar, Sachin1 aYoyakki, Athira1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/surface-anchored-ptni-alloy-network-over-sio2-ptnisio2-versatile-carbon-free-cathode-proton02981nas a2200277 4500008004100000022001400041245015800055210006900213260000800282300001600290490000700306520197400313653002102287653003202308653002102340653002902361653002202390653003802412100002002450700001802470700002402488700002402512700001802536700002402554856012502578 2025 eng d a2155-543500aA Pt-Based Carbon-Free Cathode with Embedded Oxygen Nanoreservoirs: A Promising Approach for Oxygen Buffering to Aid Oxygen Reduction Reactions of PEMFCs0 aPtBased CarbonFree Cathode with Embedded Oxygen Nanoreservoirs A cNOV a19677-196940 v153 a

For practical applications of proton exchange membrane fuel cells (PEMFCs), the system needs to be operated by employing air in the cathode instead of pure oxygen (O2). This makes it necessary to develop innovative electrode engineering solutions so that the system can function well even in oxygen-lean environments under the realistic working conditions of PEMFCs. Taking this into account, we introduce Pt/SiO2@CeO2-30%, an engineered electrocatalyst with potentially generated oxygen vacancies (Ov), which can immensely contribute toward the enhancement in the O2 availability in oxygen-lean conditions like the air feed conditions, allowing an effective control of the overpotential related to the oxygen reduction reactions (ORRs) at the electrode level. The meticulously crafted Pt-CeO2 interface serves as one of the appreciable structural attributes of the present catalyst, facilitating oxygen spillover toward the Pt environment, aided by the creation of the immense Ov along the nano CeO2 phase of the catalyst. In addition to the benefit of addressing the oxygen-lean conditions and overcoming the limitations of the state-of-the-art catalysts, usage of a noncarbonaceous support like SiO2 to house the Pt and CeO2 nanoparticles has been anticipated to lessen the corrosion problems, a major drawback associated with the carbon-based ORR catalysts. Apart from this, a significant contribution of SiO2 to the self-humidification of the ionomer interface plays a crucial role in enabling the MEA to work under low relative humidity conditions, which can be attributed to an additional benefit of the current composition of the catalyst. The catalyst demonstrated a promising ORR performance with a substantial improvement in H2-air feed circumstances and better corrosion resistance when tested with a membrane electrode assembly (MEA) in a single-cell configuration, illustrating the practical feasibility in a realistic system-level validation.

10acarbon corrosion10acarbon-free electrocatalyst10aoxygen buffering10aoxygen reductionreaction10aoxygen spill over10aprotonexchange membrane fuel cell1 aYoyakki, Athira1 aKumar, Sachin1 aPandikassala, Ajmal1 aJadhav, Swapnil, D.1 aVinod, C., P.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/pt-based-carbon-free-cathode-embedded-oxygen-nanoreservoirs-promising-approach-oxygen