Integrating Pt–Co Nanoalloy and Sulfur-Doped\nCo–N–C to Construct Oxygen Reduction Reaction Catalysts\nfor Proton Exchange Membrane Fuel Cells

Achieving\nhigh catalytic activity and stability with low platinum\nloading is vital for reducing the cost of proton exchange membrane\nfuel cells (PEMFCs) and enabling their large-scale commercialization.\nHerein, a three-dimensional (3D) nitrogen sulfur codoped carbon nanocomposite\nsupport embedded with Co nanoparticles derived from sulfur-doped zeolite\nimidazolate frameworks-67 was synthesized. After Pt nanoparticles\nare loaded, it can act as an excellent ORR catalyst (3D LPCNSC) for\nhydrogen–oxygen fuel cells. The existing metal Co are beneficial\nfor catalyzing the growth of carbon nanotubes, generating CoN<sub><i>x</i></sub> structures, and partially forming Pt–Co\nnanoalloys. Nitrogen sulfur codoping can enhance metal–support\ninteractions between Pt/Pt–Co and sulfur-doped Co–N–C\nby regulating the interfacial charge transfer. The 3D conductive network\nconstructed using graphene oxide and carbon nanotubes contributes\nto enhanced electron and mass transfer. As a result, the 3D LPCNSC\ncatalyst with a relatively lower Pt loading (13.65%) exhibits a superior\nhalf-potential, higher mass activity, and superb stability in comparison\nto commercial Pt/C (20%). A membrane electrode assembly assembled\nwith this catalyst achieves a peak power density of 983.8 mW cm<sup>–2</sup> in a hydrogen–oxygen single cell. This work\nhighlights a promising avenue for the structure and component design\nof low platinum nanocatalyst for PEMFCs.