Gd‐doped Pt₃Co Nanoparticles Embedded in Hollow Mesoporous Carbon Derived From Space‐Confined Polymerization of Indene Boosting Oxygen Reduction Reaction

Abstract Developing suitable carbon supports and efficient Pt‐based nanoparticles for the oxygen reduction reaction (ORR) is crucial for accelerating the commercialization of proton‐exchange membrane fuel cells (PEMFCs). In this study, indene‐derived hollow mesoporous carbon spheres are synthesized for the first time using space‐confined polymerization and subsequent annealing. The incorporation of Gd‐doped Pt₃Co nanoparticles into the hollow mesoporous carbon spheres (Gd‐Pt₃Co@HMS) resulted in catalysts with an impressive mass activity (MA) of 1.83 A mg_Pt⁻¹ at 0.9 V. The Gd‐Pt₃Co@HMS catalyst exhibits excellent durability, as indicated by the minimal change in its E_1/2 after 30,000 cycles. In a hydrogen‐oxygen full cell, the membrane electrode assembly (MEA) with the Gd‐Pt₃Co@HMS catalyst achieves a current density of 1.44 A cm⁻² at 0.6 V and a peak power density of 1.4 W cm⁻². This enhancement is attributed to the increased binding strength of the Pt─O bond on Gd‐Pt₃Co (111), which results in a notable reduction in ΔE_O. Additionally, the optimization of surface energy due to Gd doping contributes to the outstanding durability of the catalysts during the ORR. This research presents a novel method for developing efficient and stable oxygen reduction catalysts and has significant implications for next‐generation fuel cell applications.