Ultrahigh‐Uptake Capacity‐Enabled Gas Separation and Fruit Preservation by a New Single‐Walled Nickel–Organic Framework

High gas‐uptake capacity is desirable for many reasons such as gas storage and sequestration. Moreover, ultrahigh capacity can enable a practical separation process by mitigating the selectivity factor that sometimes compromises separation efficiency. Herein, a single‐walled nickel–organic framework with an exceptionally high gas capture capability is reported. For example, C(2)H(4) and C(2)H(6) uptake capacities are at record‐setting levels of 224 and 289 cm(3) g(−1) at 273 K and 1 bar (169 and 110 cm(3) g(−1) at 298 K and 1 bar), respectively. Such ultrahigh capacities for both gases give rise to an excellent separation performance, as shown for C(2)H(6)/C(2)H(4) with breakthrough times of 100, 60 and 30 min at 273, 283 and 298 K and under 1 atm. This new material is also shown to readily remove ethylene released from fruits, and once again, its ultrahigh capacity plays a key role in the extraordinary length of time achieved in the preservation of the fruit freshness.