近日，同济大学顾逸凡团队报道了基于Cu的金属-有机框架中的中间态双位点限域识别用于高效捕获痕量SO2（优于CO2）。该研究于2026年7月22日发表在《颗粒学报》杂志上。

从烟气中有效脱除SO₂对环境保护、人体健康以及后续的CO₂捕集过程至关重要。传统的烟气脱硫技术能耗高，且难以实现痕量SO₂的深度脱除。然而，即使是低浓度（约2000 ppm）的SO₂也会显著降低用于烟气CO₂捕集的吸附剂的性能，因此需要对富CO₂气流中的SO₂进行深度脱除。

研究组报道了一种金属有机框架材料Cu-tpo-tpt，其具有超微孔孔道，且孔道内功能化有两个反向对齐的开放Cu(II)位点。活化后，孔道内两个相对开放Cu(II)位点在几何上互补的空间排列恰好匹配弯曲的V形SO₂分子，而线性的CO₂分子尺寸则超过双Cu(II)位点之间的孔径距离。得益于这种几何匹配的双位点限域识别策略，Cu-tpo-tpt表现出对SO₂相对于CO₂的优先吸附。在298 K和0.1 bar条件下，其对SO₂的吸附容量（2.7 mmol·g^-1）显著高于CO₂（1.0 mmol·g^-1），从而对SO₂/CO₂（0.2/99.8，v/v）实现了264的优异IAST选择性。

动态穿透实验进一步证实了其出色的分离性能。机理分析表明，SO₂与Cu(II)位点之间的精确几何匹配增强了主客体相互作用，促进了在大量CO₂存在下对痕量SO₂的高选择性识别。这一发现不仅解决了痕量SO₂捕集的关键挑战，也为面向工业气体分离过程的高效吸附剂的理性设计提供了新的见解。

附：英文原文

Title: Intermediate Dual-Site Confinement Recognition in a Cu-Based Metal–Organic Framework for Efficient Capture of Trace SO2 over CO2

Author: anonymous

Issue&Volume: 2026/07/22

Abstract: Effective removal of SO2 from flue gas is critical for the environment, human health, and the following CO2 capture process. Conventional flue-gas desulfurization technologies are energy-intensive and insufficient for deep removal of such trace SO2. However, even a low concentration of SO2 (ca. 2000 ppm) can significantly degrade the performance of adsorbents employed in CO2 capture from flue gas, thus demanding its deep removal from CO2-rich gas streams. Herein, we report a metal-organic framework, Cu-tpo-tpt, which possesses ultra-microporous channels functionalized with two oppositely aligned open Cu(II) sites. Upon activation, the geometrically complementary spatial arrangement of two opposing open Cu(II) sites within the channel perfectly fits the bent V-shaped SO2 molecule, while linear CO2 exhibits a molecular size exceeding the aperture distance between the dual Cu(II) sites. Benefiting from the geometrically matched dual-site confinement recognition strategy, Cu-tpo-tpt exhibits preferential adsorption of SO2 over CO2. At 298 K and 0.1 bar, the SO2 adsorption capacity (2.7 mmol·g-1) is considerably higher than that for CO2 (1.0 mmol·g-1), leading to an exceptional IAST selectivity of 264 for SO2/CO2 (0.2/99.8, v/v). Dynamic breakthrough experiment further confirms its outstanding separation performance. Mechanistic analysis reveals that the precise geometric matching between SO2 and the Cu(II) sites enhances host-guest interactions, facilitating highly selective recognition of trace SO2 over abundant CO2. This finding not only addresses a critical challenge for trace SO2 capture, but also provides new insights for the rational design of advanced adsorbents targeting industrial gas separation processes.

DOI: 10.1016/j.partic.2026.07.010

Source: https://www.sciencedirect.com/science/article/abs/pii/S1674200126002798