Molecular-Pt/Cu-Derived Catalysts on N-Doped Carbon Fibers via In Situ Activation for Efficient HER and Potential Hydrogen Sensing

Efficient hydrogen evolution reaction (HER) catalysts are essential for improving both hydrogen production and the response performance of electrochemical hydrogen sensors. A highly active cathode catalyst (A-mPt/Cu-C) was developed by in situ electrochemical activation of molecular platinum species pre-anchored onto polyacrylonitrile (PAN)-derived carbon fibers. Structural characterizations, including SEM, EDS mapping, and XPS, reveal a graphitized carbon structure with a uniform distribution of Pt, Cu, and N species and strong electronic interactions among them. Electrochemical results demonstrate that A-mPt/Cu-C exhibits excellent HER activity in acidic media, achieving an overpotential comparable to that of commercial 20 wt % Pt/C. When assembled as the cathode of the membrane electrode assembly (MEA), it exhibits better performance when simulating the component's response to hydrogen. The enhanced catalytic performance is attributed to the synergistic effects of the carbon fiber support, nitrogen doping, and Pt–Cu interactions. This work provides a feasible strategy for developing high-efficiency HER catalysts with potential applications in hydrogen sensing.