北京化工大学孙晓明课题组近日取得一项新成果。经过不懈努力，他们实现了用于高效氧还原反应的双原子铁催化剂的升华转化合成。2024年9月03日出版的《德国应用化学》杂志发表了这项成果。

在该研究中，小组开发了一种简单直接的升华转化合成双原子铁催化剂(Fe₂/NC)的策略，利用从FeCl₃(s)原位生成的Fe₂Cl₆(g)二聚体。研究人员采用像差校正透射电子显微镜和X射线吸收精细结构(XAFS)光谱，研究了Fe₂/NC的结构。

所得Fe₂/NC继承Fe₂Cl₆的Fe-Fe距离为0.3 nm，表现出优异的氧还原性能，半波电位为0.90 V(相对于RHE)，超过了商用Pt/C催化剂、Fe单原子催化剂(Fe₁/NC)和常见的Fe-Fe距离较短的催化剂(Fe₂/NC-s)。

密度泛函理论(DFT)计算和微动力学分析表明，Fe₂/NC中Fe-Fe距离的延长对O₂在催化位点的吸附和后续质子化过程的促进至关重要，从而提高了催化性能。这项工作不仅为制造原子精度的DAC提供了一种新方法，而且对双位点催化的金属间距离效应提供了更深入的理解。

研究人员表示，双原子催化剂(DACs)由于其显著的催化活性而引起了人们的极大兴趣。然而，在DAC的制造中实现原子精确控制仍然是一个主要挑战。

附：英文原文

Title: Sublimation Transformation Synthesis of Dual-Atom Fe Catalysts for Efficient Oxygen Reduction Reaction

Author: Li Yan, Yu Mao, Yingxin Li, Qihao Sha, Kai Sun, Panpan Li, Geoffrey I. N. Waterhouse, Ziyun Wang, Shubo Tian, Xiaoming Sun

Issue&Volume: 03 September 2024

Abstract: Dual-atom catalysts (DACs) have garnered significant interest due to their remarkable catalytic reactivity. However, achieving atomically precise control in the fabrication of DACs remains a major challenge. Herein, we developed a straightforward and direct sublimation transformation synthesis strategy for dual-atom Fe catalysts (Fe2/NC) by utilizing in situ generated Fe2Cl6(g) dimers from FeCl3(s). The structure of Fe2/NC was investigated by aberration-corrected transmission electron microscopy and X-ray absorption fine structure (XAFS) spectroscopy. As-obtained Fe2/NC, with a Fe–Fe distance of 0.3 nm inherited from Fe2Cl6, displayed superior oxygen reduction performance with a half-wave potential of 0.90 V (vs. RHE), surpassing commercial Pt/C catalysts, Fe single-atom catalyst (Fe1/NC), and its counterpart with a common and shorter Fe–Fe distance of ~0.25 nm (Fe2/NC-S). Density functional theory (DFT) calculations and microkinetic analysis revealed the extended Fe–Fe distance in Fe2/NC is crucial for the O2 adsorption on catalytic sites and facilitating the subsequent protonation process, thereby boosting catalytic performance. This work not only introduces a new approach for fabricating atomically precise DACs, but also offers a deeper understanding of the intermetallic distance effect on dual-site catalysis.

DOI: 10.1002/anie.202413179

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202413179