Herein, we propose the required general pore features for one-step C2H4 production from a C2 hydrocarbon mixture, such as: (i) a non-metallic binding site; (ii) polar pore surface; and (iii) narrow pocket. Four representative MOFs (Ni-BDC-INA, CPM-173, UiO-66, and DMOF-1) and two counterexamples (MOF-74-Co and IISERP-MOF2) were selected to verify this concept, by conducting single-component gas adsorption measurements, multiple-component breakthrough experiments, and molecular simulations. The established pore features are a stepping-stone for the design and synthesis of new MOFs with improved performance for C2H4 separation.