The effect of edge-functionalization on the competitive adsorption of a binary CO2-CH4 mixture in nanoporous carbons (NPCs) has been investigated for the first time by combining density functional theory (DFT) and grand canonical Monte Carlo (GCMC) simulation. Our results show that edge-functionalization has a more positive effect on the single-component adsorption of CO2 than CH4, therefore significantly enhancing the selectivity of CO2 over CH4, in the order of NH2-NPC > COOH-NPC > OH-NPC > H-NPC > NPC at low pressure. The enhanced adsorption originates essentially from the effects of (1) the conducive environment with a large pore size and an effective accessible surface area, (2) the high electronegativity/electropositivity, (3) the strong adsorption energy, and (4) the large electrostatic contribution, due to the inductive effect/direct interaction of the embedded edge-functionalized groups. The larger difference from these effects results in the higher competitive adsorption advantage of CO2 in the binary CO2-CH4 mixture. Temperature has a negative effect on the gas adsorption, but no obvious influence on the electrostatic contribution on selectivity. With the increase of pressure, the selectivity of CO2 over CH4 first decreases sharply and subsequently flattens out to a constant value. This work highlights the potential of edge-functionalized NPCs in competitive adsorption, capture, and separation for the binary CO2-CH4 mixture, and provides an effective and superior alternative strategy in the design and screening of adsorbent materials for carbon capture and storage.

No abstract

challenges is their high overpotential generating from the four-electron process. [2] In ORR, the active sites are essential for O 2 adsorption and activation of OO bonds. [1e,3] A weakly bound oxygen state of the metals may limit the kinetic rate, while a bond that is too strong may restrict proton-electron transfer to *O and *OH. [4] For OER, the difference in free energy between *OH and *OOH is a constant (3.2 ± 0.2 eV), so the free energy of the *O plays a decisive role in the performance of OER. Either high or low *O free energy of the active sites leads to an increase in the OER overpotential. [5] Therefore, the construction of efficient oxygen electrocatalysts with customizable electronic structures, while attractive, is challenging.Atomic metal-nitrogen (MN 4 , M = Fe, Co, Ni, etc.) materials, with N-coordinated metal centers that mimic the structure of bio-porphyrins, have attracted great attention in reversible oxygen electrocatalysis. [3a,6] Their nearly 100% accessible active sites increase atom utilization and reduce costs in large-scale applications. [7] The exact geometric configurations of MN 4 species provide a shortcut to explore the correlation between their structural and electronic properties. [8] However, the inherent electronic structure and single active metal atom of MN 4Dual-metal-atom-center catalysts (DACs) are a novel frontier in oxygen electrocatalysis, boasting functional and electronic synergies between contiguous metal centers and higher catalytic activities than single-atom-center catalysts. However, the definition and catalytic mechanism of DACs configurations remain unclear. Here, a "pre-constrained metal twins" strategy is proposed to prepare contiguous FeN 4 and CoN 4 DACs with homogeneous conformations embedded in a N-doped graphitic carbon (FeCo-DACs/NC). A programmable phthalocyanines dimer is used as a structural moiety to anchor the bimetallic sites (containing Co and Fe) in a metal-organic framework (MOF) to achieve delocalized dispersion before pyrolysis. The resultant FeCo-DACs/NC exhibits excellent electrochemical performance in oxygen electrocatalysis and rechargeable Zn-air batteries. Theoretical calculations demonstrate that the synergetic interaction of adjacent metals optimizes the d-band center position of metal centers and balances the free energy of the *O intermediate, thereby improving the oxygen electrocatalytic activity. This work opens up an avenue for the rational design of DACs with tailored electronic structures and uniform geometric configurations.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202107421.