陆军工程大学李志忠研究组近日取得一项新成果。经过不懈努力，他们报道了一种稳定的钪（III）金属有机骨架，引入硝酸盐离子，提高了MTO产物分离中C₂H₆/C₂H₄的选择性。2025年3月25日出版的《结构化学》杂志发表了这项成果。

以噻吩-2,5-二羧酸（H₂Tdc）为基础，设计了一种新型的[Sc₃(μ₂-OH)₃(CO₂)₄O₆]_n无机链基的带有修饰硝酸盐离子的Sc-MOF， {[Sc₃(OH)₂(Tdc)₃(NO₃)]H₂O}_∞(AEU-1;合成了AEU，陆军工程大学专用），具有良好的水稳定性和化学稳定性。值得注意的是，由于通道收缩伴随着引入硝酸盐离子的极性窗口，AEU-1具有与许多著名的C₂H₆选择性MOFs相当的高C₂H₆/C₂H₄吸附选择性，使其成为甲醇制烯烃（MTO）产品纯化的有希望的候选者。

此外，理论研究表明，在AEU-1中引入硝酸盐离子作为主要吸附位点，可使骨架与C₂H₆/C₃H₆在全接触模式下发生强相互作用，从而提高C₂H₆和C₃H₆的吸附焓（Q_st），进一步提高C₂H₆/C₂H₄和C₃H₆/C₂H₄的吸附选择性。他们的工作为构建以无机极性为吸附位点的MOFs开辟了一条新的途径，用于高选择性地从MTO混合物中一步提纯C₂H₄和回收C₃H₆。

附：英文原文

Title: A stable scandium(III) metal-organic framework with introduced nitrate ions for enhancing C2H6/C2H4 selectivity in the separation of MTO products

Author: anonymous

Issue&Volume: 2025-03-25

Abstract: Based upon the thiophene-2,5-dicarboxylic acid (H2Tdc), a novel [Sc3(μ2-OH)3(CO2)4O6]n inorganic chain-based Sc-MOF with decorated nitrate ions, {[Sc3(OH)2(Tdc)3(NO3)]H2O}∞ (AEU-1; AEU for Army Engineering University of PLA), was synthesized, which shows good water and chemical stabilities. Significantly, due to channel constriction accompanied by the polar window caused by introducing nitrate ions, AEU-1 exhibits high C2H6/C2H4 adsorption selectivity comparable to many famous C2H6-selective MOFs, making it a promising candidate for the purification of methanol-to-olefin (MTO) products. Furthermore, theoretical investigations reveal that the introduced nitrate ions in AEU-1 as the main adsorption sites could provide strong interactions between the framework and C2H6/C3H6 in the full-contacting mode, leading to an increase in the adsorption enthalpies (Qst) of C2H6 and C3H6, and thus further improving the C2H6/C2H4 and C3H6/C2H4 adsorption selectivity. Our work could open up a new avenue for constructing MOFs with inorganic polar moieties as adsorption sites for one-step C2H4 purification and C3H6 recovery from MTO mixtures with high selectivity.

DOI: 10.1016/j.cjsc.2025.100576

Source:http://cjsc.ac.cn/cms/issues/783