The trade-off between adsorption capacity and selectivity of porous materials has been identified as a major challenge towards efficient gas separation/purification through physisorption. The research from Cui et al. address this daunting challenge by developing a new strategy that control over pore chemistry and pore size in hybrid porous materials enables the exploitation of supramolecular chemistry of gases to achieve both high capacity and selectivity, and sets new benchmarks for acetylene separation from ethylene.