Illumination enabling monoatomic Fe and Pt-based catalysts on NC/TiOx for efficient and stable oxygen reduction

Abstract

Although various alloys have been extensively explored to enhance catalyst activity and stability in oxygen reduction, degradation of performance due to long-term operation has plagued the crowd. Here, we develop a catalyst synthesis strategy based on the coexistence of monoatomic Fe and Pt-based clusters/alloys on NC/TiOx. Fe/PtCo-NC/TiOx exhibits a half-wave potential of 0.948 V and mass activity of 3.69 A mgPt−1 at 0.9 V, the latter being approximately 32.1 times higher than that of 20% Pt/C (0.115 A mgPt−1). Additionally, it also shows maximum power densities of 952.2 mW cm−2 and 215.8 mW cm−2 in the H2/O2 fuel cell and Zn-air battery, respectively. The combination of illumination and calcination promotes the electron transfer between Pt and TiOx, thus enhancing the catalytic activity and stability. We also explore the approach and mechanism of using illumination to suppress catalyst performance degradation. The intermittent irradiation inhibits the dissolution of Pt to facilitate the Fe/PtCo-NC/TiOx durability beyond that of most reported metal catalysts, with a half-wave potential degradation of only 14 mV after 30,000 cycles. The ingenious use of illumination provides a simple and feasible strategy for the sustainable utilization of catalysts.