Bidirectional modulation interaction between monatomic Pt and Tin+ sites on Ti4O7 for high-efficiency and durable oxygen reduction

Abstract

Although single atom catalyst (SAC) can maximize the atomic utilization, platinum (Pt)-based SAC is typically inactive to break the O = O bond in oxygen reduction. Herein, the nanoporous Ti4O7 was synthesized while Pt was atomically dispersed on the Ti4O7 surface by a one-step calcination method. The as-prepared Pt/Ti4O7 SAC exhibits a half-wave potential of 0.896 V and a mass activity of 4081.5 A/gPt at 0.9 V with negligible degradation after 20,000 cycles. Meanwhile, it exhibits a Pt utilization efficiency of 0.16 gPt kW−1 in H2/O2 fuel cell and a slight attenuation of the output current density (9.4%) after 120 h. The incorporated monatomic Pt electronically couples with the Tin+ (3 ≤ n < 4) to enhance bilateral electron transfer. The awakened Tin+ active sites synergize with monatomic Pt to moderate the adsorption intensity of O2 and dissociate the O = O bond, opening up a four-electron pathway on the Pt-based SAC.