Simultaneous Platinum Nanoparticle Refinement and Carbon Support Structural Modification via Intense Pulsed Light Processing for Improved Oxygen Reduction Reaction

Intense pulsed light (IPL) irradiation was used as a rapid photothermal method to prepare Pt/C oxygen reduction reaction (ORR) catalysts by converting H2PtCl6•6H2O impregnated on Vulcan XC-72 carbon with a small number of pulses (1 and 5 shots).The carbon-black framework was retained after irradiation, while crystalline Pt nanoparticles were formed on the support, as confirmed by electron microscopy.X-ray diffraction showed fcc Pt reflections, and the Pt(111) peak was broader for the 5-shot sample than for the 1-shot sample, which is qualitatively consistent with a reduction in Pt crystallite size between the two IPL conditions.Carbon-related diffraction features became sharper and the Raman (ID/IG) ratio decreased slightly with pulse number, suggesting partial ordering of the carbon support.Pt 4f XPS revealed more pronounced oxidized Pt components after a single pulse, whereas the 5-shot sample showed a higher fraction of metallic Pt species.Considering that the Pt loading values of the two IPL-treated samples were nearly identical, this difference is interpreted as reflecting a difference in Pt surface chemical-state distribution.Because Pt 4f XPS alone cannot distinguish incomplete precursor conversion from post-synthesis surface oxidation precursorderived residual species are not claimed here.Thermogravimetric analysis verified a reproducible Pt loading of ~22 wt% for the IPL-derived catalysts and showed a higher oxidation-resistance tendency for the 5-shot sample.In RDE tests (0.5 M H2SO4), the 5-shot catalyst showed improved ORR metrics relative to the 1-shot sample, including higher onset potential (0.75 vs 0.73 V), larger limiting current density at 2025 rpm (-6.52 vs -6.28 mA cm - 2 ), smaller absolute Tafel slope (-110.7 vs -126.3 mV dec -1 ), and higher EDLC (1.2 vs 0.6 mF cm -2 ).Overall, these results suggest that increasing IPL dose promotes precursor reduction and favorable Pt distribution while modestly enhancing carbon ordering, leading to improved ORR performance.