Pein, PhilipPhilipPeinAlsuhile, Ala Abdulalem Abdo MoqbelAla Abdulalem Abdo MoqbelAlsuhilePenner, SimonSimonPennerMohammadi, AsgharAsgharMohammadiZickler Gregor AlexanderAlmohammad, AseelAseelAlmohammadBaron, FinnFinnBaronKirstein, MathisMathisKirsteinErkey, CanCanErkeySmirnova, IrinaIrinaSmirnovaElsaesser, MichaelMichaelElsaesserSchroeter, BaldurBaldurSchroeter2026-03-312026-03-312026Small: e12049 (2026)https://hdl.handle.net/11420/62464This study introduces a new strategy to electrocatalyst synthesis by immobilizing platinum nanoparticles (Pt-NPs) on carbon spherogels—nanoporous, monodisperse carbon hollow spheres with diameters of 170–240 nm and surface areas of up to 800 m2 g−1 with or without incorporated titanium-dioxide (TiO2) sublayers, using supercritical deposition. The resulting materials feature precisely tunable Pt-loadings (2–11 wt%), narrow Pt-NP size distributions, low interparticle distances (4.4–8.2 nm), and high Pt-NP dispersion (Pt-NP mean diameter 2.2–3.5 nm). The presence of TiO2 sublayers enhances both catalytic activity and durability in the hydrogen evolution reaction compared to a commercial Pt/C benchmark with similar Pt content. TiO2 containing electrocatalysts exhibit Pt-NPs in the inner part of spheres and outstanding stability, demonstrated by (a) minimal potential shifts (1–4 mV) after accelerated stability tests, (b) suppression of Pt-NP growth and detachment, and (c) structural integrity retention after 70 h under harsh conditions. These findings highlight the potential of spherogels as advanced catalyst supports and offer a scalable synthesis route without requirement for hazardous templating agents. Thanks to the tunable support morphology, precise Pt-NP deposition, and remarkable long-term performance, this approach emerges as a strong candidate for designing next generation electrocatalysts.en1613-68292026Wileyhttps://creativecommons.org/licenses/by/4.0/ElectrocatalystsHydrogen Evolution ReactionCarbon SpherogelsTechnology::620: Engineering::620.5: NanotechnologyNatural Sciences and Mathematics::530: PhysicsJournal Articlehttps://doi.org/10.15480/882.1692910.1002/smll.20251204910.15480/882.16929Journal Article