Decoupling adsorption affinity and regeneration barrier via dynamic electron redistribution in Fe-Zr metal-organic...

Amid global efforts toward low-energy gas purification, we present a bimetallic metal-organic framework gel (FeU-1) that overcomes the trade-off between adsorption capacity and regeneration energy. FeU-1 achieves a high toluene uptake of 975 mg/g (P/P₀ = 0.97), while reducing the desorption activation energy from 169.1 kJ/mol (UiO-66 MOF) to 34.9 kJ/mol. In situ DRIFTS and XPS analyses reveal dynamic electron migration between Fe and Zr nodes during the adsorption-desorption cycle, validating that the reversible asymmetric electron distribution modulates metal···π interactions. DFT and AIMD simulations further identify a "parallel" bimetallic adsorption configuration and track the complete desorption trajectory of toluene, highlighting the sequential detachment of molecules from different metal sites, governed by their interaction strengths. This electron-regulation mechanism, validated in CuU-1 and AlU-1, offers a broadly applicable strategy for designing other open-shell bimetallic MOGs with tunable adsorption-desorption behavior. This work deepens the understanding of charge-regulated host-guest interactions and proposes a rational strategy for designing intelligent, energy-efficient VOC adsorbents aligned with global carbon neutrality goals.