Selective nitrogen capture by porous hybrid materials containing accessible transition metal ion sites
Selective nitrogen capture by porous hybrid materials containing accessible transition metal ion sites
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DOI：
10.1038/nmat4825
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发表时间：
2017-05-01
期刊：
影响因子：
41.2
通讯作者：
Chang, Jong-San
中科院分区：
文献类型：
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作者：
Yoon, Ji Woong;Chang, Hyunju;Chang, Jong-San
选择性二氮与过渡金属离子的结合主要涵盖两个战略领域：金属固氮酶催化的生物固氮(1-3)，以及天然气和空气的吸附净化(4-6)。许多过渡金属-二氮络合物已被设想用于仿生固氮以生产氨(3)。受这个概念的启发，我们在这里报道了含有可接近的 Cr(III) 位点的介孔金属有机骨架材料，能够通过热力学捕获 CH4 和 O-2 上的 N-2。这项整合了先进实验和计算工具的基础研究证实，N-2/CH4 和 N-2/O-2 气体混合物的分离机制是由这些不饱和 Cr(III) 位点的存在驱动的，这些不饱和 Cr(III) 位点使得 N-2 的结合比其他两种气体更强。除了基于吸附的技术的潜在突破之外，这一概念验证还可以为解决化学领域的多项挑战开辟新的视野，包括通过固氮设计异质仿生催化剂。
Selective dinitrogen binding to transition metal ions mainly covers two strategic domains: biological nitrogen fixation catalysed by metalloenzyme nitrogenases(1-3), and adsorptive purification of natural gas and air(4-6). Many transition metal-dinitrogen complexes have been envisaged for biomimetic nitrogen fixation to produce ammonia(3). Inspired by this concept, here we report mesoporous metal-organic framework materials containing accessible Cr(III) sites, able to thermodynamically capture N-2 over CH4 and O-2. This fundamental study integrating advanced experimental and computational tools confirmed that the separation mechanism for both N-2/CH4 and N-2/O-2 gas mixtures is driven by the presence of these unsaturated Cr(III) sites that allows a much stronger binding of N-2 over the two other gases. Besides the potential breakthrough in adsorption-based technologies, this proof of concept could open new horizons to address several challenges in chemistry, including the design of heterogeneous biomimetic catalysts through nitrogen fixation.