Kisand Kaarel, Sarapuu Ave, Douglin John C, Kikas Arvo, Käärik Maike, Kozlova Jekaterina, Aruväli Jaan, Treshchalov Alexey, Leis Jaan, Kisand Vambola, Kukli Kaupo, Dekel Dario R, Tammeveski Kaido
Institute of Chemistry, University of Tartu, Ravila 14a, Tartu, 50411, Estonia.
Institute of Physics, University of Tartu, W. Ostwald Str. 1, Tartu, 50411, Estonia.
ChemSusChem. 2025 Jan 14;18(2):e202401332. doi: 10.1002/cssc.202401332. Epub 2024 Oct 23.
Platinum group metal (PGM)-free electrocatalysts have emerged as promising alternatives to replace Pt for the oxygen reduction reaction (ORR) in anion exchange membrane fuel cells (AEMFCs). However, traditional synthesis methods limit the single-atom site density due to metal agglomeration at higher temperatures. This work explores the preparation of hierarchically porous atomically dispersed electrocatalysts for the ORR. The materials were prepared via ionothermal synthesis, where magnesium nitrate was used to prepare hierarchically porous carbon materials. The in-situ formed Mg-N sites were trans-metalated to yield ORR-active Fe-N sites. The resulting carbon-based catalysts displayed excellent electrocatalytic activity, attributed to the atomically dispersed Fe-N active sites and high meso- and macroporosity that enhanced the mass transport and exposed more accessible active sites.
无铂族金属（PGM）电催化剂已成为阴离子交换膜燃料电池（AEMFC）中替代铂用于氧还原反应（ORR）的有前景的替代品。然而，传统合成方法由于在较高温度下金属团聚而限制了单原子位点密度。这项工作探索了用于ORR的分级多孔原子分散电催化剂的制备。这些材料通过离子热合成制备，其中硝酸镁用于制备分级多孔碳材料。原位形成的Mg-N位点进行了金属转移以产生ORR活性的Fe-N位点。所得的碳基催化剂表现出优异的电催化活性，这归因于原子分散的Fe-N活性位点以及高介孔和大孔率，其增强了质量传输并暴露了更多可及的活性位点。
