Interfacial engineering of high-performance Fe2P2O7-based electrocatalysts for alkaline exchange membrane fuel cells.

• A ZIF-8-derived carbon (Z8C) supported Fe 2 P 2 O 7 electrocatalyst is fabricated. • The catalyst showed superior electroactivity for the four-electron ORR. • Its electrocatalytic performance and methanol tolerance are better than Pt/C. • XPS and XAS studies suggest an electron redistribution from Z8C to Fe 2 P 2 O 7. • DFT calculations show that the redistribution boosts the catalyst's intrinsic activity. Fuel cells promise high energy density and energy conversion efficiency but are plagued by the scarcity of platinum for facilitating the oxygen reduction reaction (ORR). Herein, a facile synthesis of a heterojunction electrocatalyst of ZIF-8 derived carbon (Z8C) supported Fe 2 P 2 O 7 (Fe 2 P 2 O 7 @Z8C) is reported. The electrocatalyst exhibited higher half-wave potential than the state-of-the-art Pt/C catalyst by more than 33 mV and achieved a peak power density of 152.47 mW cm−2, outperforming the Pt/C-driven cell by ca. 14.5 mW cm−2 in alkaline membrane electrode assemblies under similar operating conditions. X-ray photoelectron and X-ray absorption spectroscopic studies suggested a spontaneous electron redistribution across the heterojunction interface in Fe 2 P 2 O 7 @Z8C. Density functional theory calculations indicated that the electron redistribution may remarkably promote the intrinsic activity of Fe 2 P 2 O 7 @Z8C toward the four-electron ORR pathway. These findings offer an indispensable strategy for rational design of highly efficient and durable non-noble electrocatalysts. [Display omitted] [ABSTRACT FROM AUTHOR]