Tuning the Spin State of the Iron Center by Bridge-Bonded Fe-O-Ti Ligands for Enhanced Oxygen Reduction
Tuning the Spin State of the Iron Center by Bridge-Bonded Fe-O-Ti Ligands for Enhanced Oxygen Reduction
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DOI：
10.1002/anie.202117617
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发表时间：
2022-03-21
影响因子：
16.6
通讯作者：
Wang, Bo
中科院分区：
文献类型：
--
作者：
Liu, Yarong;Liu, Xiangjian;Wang, Bo
探索功能衬底和精确调控具有中等自旋态的原子金属活性物种的电子结构具有重要意义，但仍然具有挑战性。在此基础上，我们提出了一种轴向Fe-O-Ti配体调控的自旋态转变策略，以提高Fe中心的氧还原反应（ORR）活性。理论计算表明，FeN 3-O-O-Ti中的Fe-O-Ti配体可以诱导低-中自旋态转变，优化FeN 3 O对O-2的吸附。作为概念验证，定向催化剂由原子Fe掺杂的聚合物样量子点和双氧封端的MXene制备。最佳催化剂表现出的固有活性几乎是对照样品（没有轴向Fe-O-Ti配体）的5倍。它还在锌空气电池和H-2/O-2阴离子交换膜燃料电池中在宽温度范围内提供了上级性能。
Exploring functional substrates and precisely regulating the electronic structures of atomic metal active species with moderate spin state are of great importance yet remain challenging. Hereon, we provide an axial Fe-O-Ti ligand regulated spin-state transition strategy to improve the oxygen reduction reaction (ORR) activity of Fe centers. Theoretical calculations indicate that Fe-O-Ti ligands in FeN3-O-O-Ti can induce a low-to-medium spin-state transition and optimize O-2 adsorption by FeN3O. As a proof-of-concept, the oriented catalyst was prepared from atomic-Fe-doped polymer-like quantum dots and ultrathin o-terminated MXene. The optimal catalyst exhibits an intrinsic activity that is almost 5 times higher than the control sample (without axial Fe-O-Ti ligands). It also delivers a superior performance in Zn-air batteries and H-2/O-2 anion exchange membrane fuel cells in a wide-temperature range.