Pt Single Atoms and\nClusters Supported on N‑Doped\nPorous Carbon for Improved Hydrogen Evolution Reaction

Platinum is renowned for its exceptional catalytic performance\nin the hydrogen evolution reaction (HER), but its high cost and rarity\nseriously hinder the large-scale application of platinum electrocatalysts.\nConstructing highly dispersed platinum active sites is an effective\nstrategy to lower the loading of Pt while maintaining high activity.\nHerein, a highly dispersed Pt catalyst composed of a mixture of single\natoms and clusters is synthesized on porous N-doped carbon (Pt/N-PC)\nderived from renewable peony. The existence of Pt single atoms and\nclusters was confirmed by combining methods such as aberration-corrected\nhigh-angle annular dark field-scanning transmission electron microscopy\nimages (HAADF-STEM), X-ray absorption fine structure (XAFS), and X-ray\nphotoelectron spectroscopy (XPS). The Pt/N-PC catalyst exhibits superior\nperformance compared to the Pt-free catalyst (N-PC) as well as to\nthe commercial 20 wt % Pt/C catalyst. It exhibits an overpotential\nof just 11 mV at a current density of 10 mA/cm<sup>2</sup>, a Tafel\nslope of 24.1 mV/dec, and an exceptional long-term durability in acidic\nenvironments. Notably, upon optimizing the geometric loading amount\nof Pt, the optimal catalyst achieves an ultrahigh platinum mass activity\nof 3.44 A mg<sup>–1</sup><sub>Pt</sub> at a potential of −50\nmV. This value is approximately 9.5 times greater than that of the\ncommercial 20 wt % Pt/C catalyst (0.36 A mg<sup>–1</sup><sub>Pt</sub>).