Fan Chenming, Gao Xin, Tang Pengyi, Wang Qiang, Li Bing
School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China.
2020 X-Lab, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, P. R. China.
Adv Sci (Weinh). 2025 Feb;12(8):e2410784. doi: 10.1002/advs.202410784. Epub 2024 Dec 31.
Precious metal-based single-atom catalysts (PM-SACs) hosted in N-doped carbon supports have shown new opportunities to revolutionize cathodic oxygen reduction reaction (ORR). However, stabilizing the high density of PM-N sites remains a challenge, primarily due to the inherently high free energy of isolated metal atoms, predisposing them to facile atomic agglomeration. Herein, a molten salt-assisted synthesis strategy is proposed to prepare porous PM/N-C (PM = Ru, Pt, and Pd) electrocatalysts with densely accessible PM-N sites. A hierarchically porous N-doped carbon substrate (N-C), synthesized via the NaCl-assisted pyrolysis of zeolitic imidazolate framework-8, effectively improves the utilization of PM-N sites by increased reactants accessible surface area and reduced mass transfer resistance. In accordance with theoretical calculations, the as-prepared Ru/N-C, featuring superior intrinsic active Ru-N sites, exhibit outstanding ORR turnover frequency of 6.19 e site s, and outperforms the commercial Pt/C with a 5.3-fold of mass activity (5.83 ± 0.61 A mg) at 0.8 V versus reversible hydrogen electrode. The commendable activity and stability of Ru/N-C in a real fuel cell device further affirm its practical applicability.
负载于氮掺杂碳载体上的贵金属基单原子催化剂（PM-SACs）为阴极氧还原反应（ORR）带来了变革的新机遇。然而，稳定高密度的PM-N位点仍然是一个挑战，这主要是由于孤立金属原子固有的高自由能，使其易于发生原子团聚。在此，我们提出了一种熔盐辅助合成策略，以制备具有密集可及PM-N位点的多孔PM/N-C（PM = Ru、Pt和Pd）电催化剂。通过NaCl辅助热解沸石咪唑框架-8合成的分级多孔氮掺杂碳载体（N-C），通过增加反应物可及表面积和降低传质阻力，有效提高了PM-N位点的利用率。根据理论计算，所制备的具有优异本征活性Ru-N位点的Ru/N-C，表现出6.19 e site s的出色ORR周转频率，在相对于可逆氢电极0.8 V时，其质量活性比商业Pt/C高5.3倍（5.83±0.61 A mg）。Ru/N-C在实际燃料电池装置中的优异活性和稳定性进一步证实了其实际应用价值。
