02156nas 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-reduction03376nas a2200337 4500008004100000022001400041245023000055210006900285260000800354490000700362520209900369653000702468653002602475653001402501653002702515653001802542653003002560653003002590653003402620653003402654100003002688700002002718700003302738700001802771700002702789700002002816700001802836700003602854700002402890856012402914 2024 eng d a1613-681000aAluminium, nitrogen-dual-doped reduced graphene oxide Co-existing with cobalt-encapsulated graphitic carbon nanotube as an activity modulated electrocatalyst for oxygen electrocatalyst for oxygen electrochemistry applications0 aAluminium nitrogendualdoped reduced graphene oxide Coexisting wi cAUG0 v203 a

There is a rising need to create high-performing, affordable electrocatalysts in the new field of oxygen electrochemistry. Here, a cost-effective, activity-modulated electrocatalyst with the capacity to trigger both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in an alkaline environment is presented. The catalyst (Al, Co/N-rGCNT) is made up of aluminium, nitrogen-dual-doped reduced graphene oxide sheets co-existing with cobalt-encapsulated carbon nanotube units. Based on X-ray Absorption Spectroscopy (XAS) studies, it is established that the superior reaction kinetics in Al, Co/N-rGCNT over their bulk counterparts can be attributed to their electronic regulation. The Al, Co/N-rGCNT performs as a versatile bifunctional electrocatalyst for zinc-air battery (ZAB), delivering an open circuit potential approximate to 1.35 V and peak power density of 106.3 mW cm-2, which are comparable to the system based on Pt/C. The Al, Co/N-rGCNT-based system showed a specific capacity of 737 mAh gZn-1 compared to 696 mAh gZn-1 delivered by the system based on Pt/C. The DFT calculations indicate that the adsorption of Co in the presence of Al doping in NGr improves the electronic properties favoring ORR. Thus, the Al, Co/N-rGCNT-based rechargeable ZAB (RZAB) emerges as a highly viable and affordable option for the development of RZAB for practical applications. This manuscript reports the development of a new bifunctional catalyst that exhibits high activity and stability under practical operating conditions. The catalyst (Al, Co/N-rGCNT) is made up of aluminium, nitrogen-dual-doped reduced graphene oxide sheets co-existing with the in situ formed cobalt-encapsulated CNT units is synthesized by a scalable pyrolysis method in an inert Ar atmosphere. The developed electrocatalyst achieved enhanced the oxygen reduction reaction (ORR) and the oxygen evolution reaction OER activity as a result of the favorable synergistic modulations and the system can serve as a process-friendly air-electrode for rechargeable zinc-air battery (RZAB). image

10aAl10aBifunctional catalyst10aDFT study10aencapsulated structure10aN-dual doping10aOxygen Evolution Reaction10aoxygen reduction reaction10arechargeable zinc-air battery10aX-ray absorption spectroscopy1 aKharabe, Geeta, Pandurang1 aBarik, Sidharth1 aVeeranmaril, Sudheesh, Kumar1 aNair, Aathira1 aIllathvalappil, Rajith1 aYoyakki, Athira1 aJoshi, Kavita1 aVinod, Chathakudath, Prabhakara1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/aluminium-nitrogen-dual-doped-reduced-graphene-oxide-co-existing-cobalt-encapsulated02452nas a2200229 4500008004100000022001400041245013900055210006900194260000800263490000600271520157000277653003001847653003001877653004301907100002401950700002701974700002202001700002402023700002002047700002402067856013102091 2025 eng d a2366-748600aPt-based 3D electrocatalyst with process-friendly features for PEMFCs possessing fast activation and improved mass-transfer properties0 aPtbased 3D electrocatalyst with processfriendly features for PEM cAPR0 v93 a

Polymer-electrolyte-membrane fuel cells (PEMFCs) face the challenges like slow oxygen reduction reaction (ORR) kinetics and limited mass transport at high current densities, which affects their performance. The efficient water removal from the cathode is essential to improve oxygen diffusion. Addressing this, a catalyst is presented with platinum (Pt) nanoparticles distributed within a 3D carbon network (Pt/3DPDC) derived from the polydopamine-coated melamine foam. This unique architecture enhances Pt utilization and water management due to its high porosity and ample free spaces, providing a process-friendly feature for the electrode under PEMFC conditions. The pores and accessible texture of the 3D polydopamine derived carbon (3DPDC) framework facilitate ionomer uptake during the electrode fabrication, extending the active triple-phase boundary and improving the membrane electrode assembly (MEA) performance. The high porosity of Pt/3DPDC is mitigated by adding a small amount of commercial fuel cell catalayst (Pt/C), which maintains the effective catalyst number density per unit area by utilizing the excess porosity of the 3DPDC framework. This controlled interplay of the unique catalyst structure and spatially confined distribution of Pt/C within the Pt/3DPDC framework offers fast activation, reduced electrode flooding, and improved current densities across the operating potential window. This carefully engineered catalyst, designed through bottom-up strategies, is a promising electrocatalyst for practical PEMFC applications.

10aOxygen Evolution Reaction10aoxygen reduction reaction10arechargeable flexible zinc-air battery1 aPandikassala, Ajmal1 aNadumattuvayil, Varsha1 aSingh, Mayank, U.1 aJadhav, Swapnil, D.1 aYoyakki, Athira1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/pt-based-3d-electrocatalyst-process-friendly-features-pemfcs-possessing-fast-activation-and