The separation of methane (CH₄) and nitrogen (N₂) in coalbed methane (CBM) is a crucial process to produce methane as a clean energy source. Given the similar physicochemical properties of the two gases, efficient adsorptive separation of CH₄ and N₂ has stringent requirements on the pore chemistry and geometry of the adsorbents. In this study, we report two Zn-pyrazolates frameworks, HIAM-213 and HIAM-214, which possess Lewis basic sites that exhibit precise recognition of CH₄ over N₂. The capability of these compounds in extracting CH₄ from binary CH₄/N₂ mixtures has been confirmed through column breakthrough measurements, demonstrating a high recovery rate under mild regeneration conditions. Grand canonical Monte Carlo simulations and in situ Fourier transform infrared spectroscopy experiments provide insights into the selective adsorption mechanism by revealing stronger interactions between CH₄ and Lewis acid sites.

中文翻译：

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将 Lewis 碱性位点掺入 Zn-吡唑酸盐框架中，以实现高效的甲烷/氮分离


煤层气 （CBM） 中甲烷 （CH₄） 和氮气 （N₂） 的分离是生产甲烷作为清洁能源的关键过程。鉴于这两种气体的物理化学性质相似，CH₄ 和 N₂ 的高效吸附分离对吸附剂的孔隙化学和几何形状有严格的要求。在这项研究中，我们报道了两个 Zn-吡唑酸盐框架，HIAM-213 和 HIAM-214，它们具有 Lewis 基本位点，表现出对 CH₄ 而不是 N₂ 的精确识别。这些化合物从二元 CH₄/N₂ 混合物中提取 CH₄ 的能力已通过色谱柱穿透测量得到证实，在轻度再生条件下具有高回收率。大经典蒙特卡洛模拟和原位傅里叶变换红外光谱实验通过揭示 CH₄ 和路易斯酸位点之间更强的相互作用，提供了对选择性吸附机制的见解。