Mn atomic clusters and Fe nanoparticles in-situ confined nitrogen carbon nanotubes for efficient and durable ORR electrocatalysts in both alkaline and acidic media
Mn atomic clusters and Fe nanoparticles in-situ confined nitrogen carbon nanotubes for efficient and durable ORR electrocatalysts in both alkaline and acidic media
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DOI：
10.1016/j.jallcom.2023.169992
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发表时间：
2023-04
影响因子：
6.2
通讯作者：
Xinqing Guo;Song Xue;Xiaohua Zhang;Junfeng Qin;Min Hong;Qinqin Chen;Wuhua Liu;Cuicui Du;Jinhua Chen
中科院分区：
文献类型：
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作者：
Xinqing Guo;Song Xue;Xiaohua Zhang;Junfeng Qin;Min Hong;Qinqin Chen;Wuhua Liu;Cuicui Du;Jinhua Chen
开发用于碱性和酸性介质的坚固耐用的非贵金属 ORR 电催化剂仍然具有挑战性。在此，通过高温煅烧和同时化学气相沉积的简便一步法制备了高度分散的Mn原子团簇和独立的Fe纳米颗粒双位点原位限域氮掺杂碳纳米管（Mn-Fe@NCNT）。所得到的Mn-Fe@NCNTs催化剂由于其特殊的组成和结构，在碱性和酸性介质中均表现出优异的ORR催化活性和耐久性，不仅提供了丰富的活性位点和缺陷、良好的电子导电性和有效的电子转移，而且增强了催化剂的耐腐蚀性并降低了芬顿反应活性。在 0.1 M KOH 溶液中，Mn-Fe@NCNT 的半波电位为 0.872 V，比商用 Pt/C 催化剂 (E1/2= 0.835 V) 和许多其他先前报道的基于 NCNT 的非贵金属 ORR 电催化剂更正。而在 0.1 M HClO4 溶液中，Mn-Fe@NCNT 的半波电位为 0.760 V，与 Pt/C 催化剂相比仅负移 60 mV。此外，与 Pt/C 在碱性和酸性溶液中的催化剂相比，所制备的催化剂在连续 29,000 秒计时电流测试和连续 5,000 次循环 CV 测试后表现出更高的稳定性，电流衰减更低，ORR 极化曲线偏移更小。当应用于锌空气电池测试时，Mn-Fe@NCNTs电催化剂的比容量为774.0 mAh g−1Zn，功率密度为139.2 mW cm−2，明显优于商业Pt/C。这项研究为开发应用于燃料电池、金属空气电池和许多其他清洁电化学存储装置的低成本和高效电催化剂提供了一种简便且具有指导意义的方案。
Developing robust and durable nonprecious metal ORR electrocatalysts for use in both alkaline and acidic media is still challenging. Herein, highly dispersed Mn atomic clusters and standalone Fe nanoparticles dual-sites in-situ confined nitrogen doped carbon nanotubes (Mn-Fe@NCNTs) were fabricated via a facile one-step process of high-temperature calcination and simultaneous chemical vapor deposition. The resultant Mn-Fe@NCNTs catalysts exhibited excellent ORR catalytic activity and durability in both alkaline and acidic media due to the special constitute and structure, which not only provided abundant active sites and defects, good electronic conductivity and effective electron transfer, but also enhanced the corrosion resistance and decreased the Fenton reactivity of the catalyst. In 0.1 M KOH solution, the half-wave potential of Mn-Fe@NCNTs is 0.872 V, more positive than that of the commercial Pt/C catalyst (E1/2= 0.835 V) and many other previously reported NCNTs based non-precious metal ORR electrocatalysts. While in 0.1 M HClO4solution, Mn-Fe@NCNTs exhibits a half-wave potential of 0.760 V, only 60 mV negative shift compared to the Pt/C catalyst. Furthermore, the as-prepared catalysts exhibit much higher stability, with much lower current attenuation and smaller shift of the ORR polarization curves after continuous chronoamperometric testing for 29,000 s and continuous CV test for 5,000 cycles, than those of Pt/C in both alkaline and acidic solutions. When applied in Zn-air batteries for testing, the Mn-Fe@NCNTs electrocatalysts are obviously outperforming the commercial Pt/C with higher specific capacity of 774.0 mAh g−1Znand power density of 139.2 mW cm−2. This study offers a facile and instructive protocol for developing low-cost and high-efficiency electrocatalysts to be applied in fuel cells, metal-air cells and many other clean electrochemical storage devices.