A Spatially Confined gC₃N₄–Pt Electrocatalyst with Robust Stability

Metal catalysts (e.g., Pt) have a variety of applications in energy conversion devices including polymer electrolyte fuel cells (PEFCs); however, they commonly confront a crucial issue of poor stability. Herein, a structural model of spatially confining supported Pt nanoparticles is determined to improve the stability of metal catalysts, wherein graphitic carbon nitride (gC3N4) supported Pt nanoparticles (gC3N4–Pt) are spatially confined by carbon nanospheres (CNSs). The resulting CNSs-Pt/gC3N4 catalyst demonstrates a surprising retention rate of electrochemical surface area as high as 85.0%, much higher than that of the commercial Pt/C catalyst (45.2%), and the half-wave potential is reduced by only 11 mV compared with 54 mV for Pt/C after 6000 scanning cycles. In addition, CNSs also serve as a conductive agent to increase electron transfer pathways on Pt surfaces, and the unique spatial confinement structure with an open framework ensures the mass transfer. Moreover, the methanol oxidation reaction (MOR) activity of CNSs-Pt/gC3N4 gets elevated by 2.1 times that of Pt/C in terms of the anodic peak current. The stabilized catalyst model and its derivative structures can be applied to various metal catalyst systems.