Liquid-Phase Synthesis of PtM₃ Intermetallic Catalysts for Hydrogen Evolution and Oxygen Reduction Reactions

Reducing the Pt load in the cathode while still maintaining high activity and stability is extremely significant for a sustainable energetic future. Herein, we reported a liquid-phase synthesis strategy for the preparation of low-Pt ordered PtM 3 (M = Mn, Cu, Co) intermetallic nanoparticles (NPs) supported on N-doped carbon nanotubes (denoted as O-PtM 3 /NCNT) catalysts. Taking the O-PtMn 3 /NCNT as an example, it exhibited efficient and durable hydrogen evolution (HER) and oxygen reduction (ORR) reactions in acidic media. Compared to commercial Pt/C, ordered O-PtMn 3 /NCNT presented a relatively low overpotential for HER (η 10 = 10.8 mV) and a relatively large half-wave potential for ORR ( E 1/2 = 0.88 V) and the O-PtMn 3 /NCNT nanoelectrocatalyst exhibited 1.9-fold and 4.4-fold increase in mass activity for HER and ORR, respectively, as well as fascinating stability behavior in acidic media. A proton exchange membrane water electrolysis (PEMWE) employing the ordered PtMn 3 catalyst performed at a low voltage of 1.98 V at 2 A cm –2 and remained stable for 100 h at 250 mA cm –2 . Density functional theory simulations indicate that the superior ORR performance of ordered PtMn 3 can be attributed to the more advantageous oxygen adsorption energy of Pt atoms.