02744nas a2200253   4500008004100000022001400041245019800055210006900253260000900322300001600331490000600347520172200353653003302075653002102108653002102129653006502150653002402215653002202239653003102261100002202292700002002314700002402334856013202358       2025                        eng d  a2574-096200a3D-architectured Pt-carbon electrodes for PEM fuel cells with tuned porosity and ionomer distribution-a micromanaged approach for improving activation, ohmic, and mass transport characteristics0 a3Darchitectured Ptcarbon electrodes for PEM fuel cells with tune  cDEC   a18158-181700 v83 a<p>
	The conventional catalyst layer in Proton Exchange Membrane Fuel Cells (PEMFCs) suffers the limitation of masked active sites, hindered proton transportation, excessive water clogging, and irregular ionomer distribution, resulting in an underutilized catalyst. To overcome these challenges, an innovative catalyst layer (CL) is constructed by aligning Vulcan carbon (VC) particles along a 3D carbon nitride interconnected network originating from a melamine sponge. This forms a robust scaffold rich in anchoring sites like sulfur and nitrogen for the Pt nanoparticle. The resultant 3D CL exhibits a doubled through-plane proton transport conductivity from 23 to 41 mS cm-1, delivering a 17.3% increase in the current density at 0.60 V compared to a conventional VC CL. This strategy enables enhanced ionomer incorporation, yielding a 19.60% enhancement in the ionomer coverage over the Pt without sacrificing the porosity, as verified by a mercury porosimeter. Kelvin probe force microscopy confirms a more uniform electron density across the 3D CL, in contrast to the traditional CL, suggesting uniform coverage. The advanced porosity and structure of the 3D CL allow the mass transport regions to shift to higher current densities, with an increase of 0.30 A cm-2 at 0.50 V compared to the VC CL. The improved ionomer coverage also demonstrates 19% lower voltage degradation at 0.80 A cm-2. Further, the impedance mapping across the entire current range graphically illustrates the 3D CL's advantage in the activation, Ohmic, and mass transport regions, showing a parabolic profile with a flattened bottom attributed to the reduced Ohmic resistance and its extension to delay the mass transport losses.</p>
10a3D-structured catalyst layer10aimpedancemapping10aionomer coverage10alow-temperature proton exchange membranefuel cell (LT-PEMFC)10amercury porosimeter10aproton resistance10atriplephase boundary (TPB)1 aSingh, Mayank, U.1 aMathew, Grigory1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/3d-architectured-pt-carbon-electrodes-pem-fuel-cells-tuned-porosity-and-ionomer-distribution