Metal-Organic Framework with Space-Partition Pores by Fluorinated Anions for Benchmark CH/CO Separation

The efficient separation of CH from CH/CO or CH/CO/CH mixtures is crucial for achieving high-purity CH (>99%), essential in producing contemporary commodity chemicals. In this report, we present ZNU-12, a metal-organic framework with space-partitioned pores formed by inorganic fluorinated anions, for highly efficient CH/CO and CH/CO/CH separation. The framework, partitioned by fluorinated SiF anions into three distinct cages, enables both a high CH capacity (176.5 cm/g at 298 K and 1.0 bar) and outstanding CH selectivity over CO (13.4) and CH (233.5) simultaneously. Notably, we achieve a record-high CH productivity (132.7, 105.9, 98.8, and 80.0 L/kg with 99.5% purity) from CH/CO (v/v = 50/50) and CH/CO/CH (v/v = 1/1/1, 1/1/2, or 1/1/8) mixtures through a cycle of adsorption-desorption breakthrough experiments with high recovery rates. Theoretical calculations suggest the presence of potent "2 + 2" collaborative hydrogen bonds between CH and two hexafluorosilicate (SiF) anions in the confined cavities.