Synthesis of a high performance low-platinum PtAg/C alloyed oxygen reduction catalyst through the gradualness reduction method
In order to reduce the platinum usage and increase the efficiency of noble metal utilization in the oxygen reduction catalysis, Ag is used as one of the assistant reductants and part of the upholders as well as the sacrificed template to prepare a low platinum PtAg/C catalyst through a gradualness reduction method with the final Pt mass percentage of 10.86 wt.%. This as-synthesized low platinum PtAg/C catalyst exhibits excellent oxygen reduction reaction activity and durability in acid. With only 54.77% Pt usage, the half-wave potential of PtAg/C is 28 mV higher than the commercial Pt/C and the limited diffusion current density is 1.1 times to Pt/C. Electrochemical activity surface area is 2.28 times as high as the commercial Pt/C. The area specific activity and mass activity are approximately 1.85 and 4.22 times to Pt/C, respectively. PtAg/C catalyst still displays extraordinary ORR performance with higher remaining limited current density and half-wave potential than the commercial Pt/C after 10000 potential cycles in HClO4. PtAg/C is more active and stable for ORR catalysis in acid.