@article{Kumar2023, 
author = {Rohit Kumar and Marek Mooste and Zubair Ahmed and Srinu Akula and Ivar Zekker and Margus Marandi and Maike Käärik and Jaan Leis and Arvo Kikas and Alexey Treshchalov and Markus Otsus and Jaan Aruväli and Vambola Kisand and Aile Tamm and Kaido Tammeveski},
title = {Highly active ZIF-8@CNT composite catalysts as cathode materials for anion exchange membrane fuel cells},
year = {2023},
journal = {Industrial Chemistry & Materials},
volume = {1},
number = {4},
pages = {526-541},
keywords = {Rotating disk electrode, Anion exchange membrane fuel cell, Zeolitic imidazolate framework, Non-precious metal catalyst, Oxygen reduction reaction},
url = {https://www.sciopen.com/article/10.1039/d3im00081h},
doi = {10.1039/d3im00081h},
abstract = {Developing non-precious metal-based inexpensive and highly active electrocatalysts for the oxygen reduction reaction (ORR) in alkaline media is important for fuel cell applications. Herein, we report a simple and effective synthesis of transition-metal-doped zeolitic imidazolate framework-8 (ZIF-8) and carbon nanotube (CNT) composite catalysts (ZIF-8@CNT) prepared via high-temperature pyrolysis at 900 ℃. The catalysts were characterized using different physicochemical techniques and employed as cathode materials in anion exchange membrane fuel cells (AEMFC). The prepared metal-free (ZNT-900), single-metal-doped (Fe-ZNT-900, Co-ZNT-900) and binary-metal-doped (Fe1Co1-ZNT-900, Fe1Co2-ZNT-900) catalysts had a sufficient amount of N-doping with the presence of FeCo moieties in the carbon skeleton of the latter two materials. N2 adsorption–desorption isotherms showed that all the prepared catalysts possess a sufficient Brunauer–Emmett–Teller surface area with more micropores present in ZNT-900, while a combined micro–mesoporous structure was obtained for transition-metal-doped catalysts. Binary-metal-doped catalysts showed the highest number of ORR-active sites (pyridinic-N, pyrrolic-N, graphitic-N, M–Nx) and exhibited a half-wave potential (E1/2) of 0.846 and 0.847 V vs. RHE for Fe1Co1-ZNT-900 and Fe1Co2-ZNT-900, respectively, which surpassed that of the commercial Pt/C catalyst (E1/2 = 0.834 V). In H2–O2 AEMFCs, the Fe1Co2-ZNT-900 catalyst delivered a maximum power density (Pmax) of 0.171 W cm−2 and current density at 0.5 V (j0.5) of 0.326 A cm−2, which is very close to that of the Pt/C catalyst (Pmax = 0.215 W cm−2 and j0.5 = 0.359 A cm−2). The prepared ZIF-8@CNT catalysts showed remarkable electrocatalytic ORR activity in 0.1 M KOH solution and fuel cell performance comparable to that of the benchmark Pt/C catalyst.}
}