A Large-Scalable Synthesis of Highly Efficient Pt-Ni Alloy Electrocatalyst for Proton Exchange Membrane Fuel Cells

Large-scale preparation of ordered intermetallic PtM/C alloy catalysts is essential to advance the development of proton exchange membrane fuel cells (PEMFCs). Herein, ordered Pt₃Ni-600J alloy catalysts were synthesized using impregnation reduction as well as secondary high-temperature pyrolytic reduction, and the effect of carbon with different specific surface areas and graphitization as support on oxygen reduction reaction (ORR) performance was compared. The ordered intermetallic compound Pt₃Ni nanocatalyst not only exhibits stronger atomic interaction between Pt and Ni, resulting in high chemical and structural stability of the catalysts, but also can be tuned by adjusting the Ni/Pt component ratio in order to obtain higher ORR catalytic activity. The results show that the ordered Pt₃Ni-600J alloy catalyst exhibits high ORR activity with half-wave potentials of 0.87 V compared to other catalysts obtained with different carbon carriers. In PEMFCs, the power density of Pt₃Ni-600J exceeded 2 W cm^-2 under H₂-O₂ conditions. More significantly, we have achieved the synthesis of a single batch of catalysts larger than 100 g using an indigenously designed fluidized bed pyrolysis method with a half-wave potential only 25 mV different from that synthesized in a small scale, and also showed good durability.