Tuning oxygen reduction reaction activity via structure orientation and surface arrangement: A study on ordered PtCo/C catalysts

A facile and general strategy for the preparation of highly dispersed PtCo/C catalysts with a Pt-enriched surface is reported. The thermal treatment of the PtCo/C catalyst changes the structure orientation from disordered to ordered phase. Ordered PtCo/C intermetallic catalyst exhibits significantly enhanced electrocatalytic activity and durability toward oxygen reduction reaction (ORR) compared with its disordered counterpart and commercially available PtCo/C, with a mass activity and specific activity of 0.68 A mg Pt−1@0.90 V and 1.15 mA cm−2, respectively. In addition, the mass activity only decreased by 25.1% after 30,000 potential cycles from 0.60 to 1.00 V at a scan rate of 100 mV s−1. Therefore, the improved ORR activity and stability can be ascribed to the atomic ordered surface arrangement and reasonable surface compress strain originated from Pt-enriched surface.