In-situ growth of iron phosphide encapsulated by carbon nanotubes decorated with zeolitic imidazolate framework-8 for enhancing oxygen reduction reaction

A non-precious metal electrocatalyst was obtained through the in-situ growth of iron phosphide (Fe2P) encapsulated by carbon nanotubes (CNTs) decorated with zeolitic imidazolate framework-8 (ZIF-8). Upon pyrolysis at a specific temperature, the ZIF-8/Fe2P@CNT catalyst exhibits high oxygen reduction reaction (ORR) ability and is close to the ideal electron transfer, which number is 3.99. The structure, high number of nitrogencontaining functional groups, and suitable surface properties of ZIF-8/Fe2P@CNT are critical for enhancing the ORR activity. ZIF-8/Fe2P@CNT exhibits a decay in electrocatalytic activity of 26 mV in the half-wave potential after 30 000 cycles, which is considerably superior to the decay of 123 mV for Pt/C after the same number of cycles. Therefore, ZIF-8/ Fe2P@CNT exhibits excellent ORR activity and long-term stability and can be used as a fuel cell catalyst. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

A highly efficient non-precious metal electrocatalyst was obtained through in-situ growth of iron phosphide encapsulated by carbon nanotubes decorated with zeolitic imidazolate framework-8. The catalyst exhibits close to ideal electron transfer and high oxygen reduction reaction (ORR) activity, along with long-term stability.