High-capacity sieving of C₃F₆ and C₃F₈ by a copper-based MOF with interconnected gourd-shaped channels

Targeting the challenging purification of electronic-grade C₃F₈, we report the size-sieving separation of C₃F₆ and C₃F₈ by a robust copper-based metal-organic framework, CuHTPO, that features a distinctive interconnected "gourd"-shaped pore architecture. This compound completely excludes C₃F₈ while strongly adsorbing C₃F₆, achieving an adsorption capacity as high as 71.3 cm³ g^-1 at 298 K and 100 kPa. Dynamic breakthrough experiments demonstrate the direct production of ultra-high-purity C₃F₈ (>5N) from a C₃F₆/C₃F₈ (10 : 90, v/v) gas mixture. The underlying size-sieving-based separation mechanism is corroborated by in situ infrared spectroscopy and density functional theory calculations.