A metal-organic framework (JNU-3a) with dynamic molecular pockets along one-dimensional channels enables the one-step removal of ethylene (C₂H₄) from mixtures containing C₂–C₄ alkynes. This material effectively separates ethylene from acetylene (C₂H₂), propyne (C₃H₄), and 1-butyne (1-C₄H₆) with high purity (≥99.9995%) in a single adsorption step. Laboratory-scale experiments on 1.4 g of JNU-3a showed that all alkynes break through the column at similar times, allowing for high-purity ethylene separation. Pilot-scale experiments on 107 g of JNU-3a demonstrated the collection of ethylene in a gas cylinder, with an average of 76.1 g of high-purity ethylene per cycle over 30 runs. The material's dynamic molecular pockets allow for efficient separation without competition among the alkynes, making it suitable for industrial ethylene purification. JNU-3a's structure enables selective adsorption of alkynes due to its unique pore geometry and surface chemistry, which enhances its performance compared to other MOFs. The material shows excellent recyclability and stability under various conditions, including humidity and different flow rates. The study highlights the potential of JNU-3a for efficient and cost-effective ethylene purification from alkyne mixtures.A metal-organic framework (JNU-3a) with dynamic molecular pockets along one-dimensional channels enables the one-step removal of ethylene (C₂H₄) from mixtures containing C₂–C₄ alkynes. This material effectively separates ethylene from acetylene (C₂H₂), propyne (C₃H₄), and 1-butyne (1-C₄H₆) with high purity (≥99.9995%) in a single adsorption step. Laboratory-scale experiments on 1.4 g of JNU-3a showed that all alkynes break through the column at similar times, allowing for high-purity ethylene separation. Pilot-scale experiments on 107 g of JNU-3a demonstrated the collection of ethylene in a gas cylinder, with an average of 76.1 g of high-purity ethylene per cycle over 30 runs. The material's dynamic molecular pockets allow for efficient separation without competition among the alkynes, making it suitable for industrial ethylene purification. JNU-3a's structure enables selective adsorption of alkynes due to its unique pore geometry and surface chemistry, which enhances its performance compared to other MOFs. The material shows excellent recyclability and stability under various conditions, including humidity and different flow rates. The study highlights the potential of JNU-3a for efficient and cost-effective ethylene purification from alkyne mixtures.