Hierarchically Porous, Single Zn Atom-Embedded Carbon Molecular Sieves for H2 Separations

Hierarchically porous materials containing sub-nm pores with molecular sieving abilities and microcavities with high gas diffusivity may realize energy-efficient membranes for gas separations. However, rationally designing and constructing such pores into large-area membranes enabling superior H2 purification remains challenging. Here we report the synthesis and utilization of hybrid carbon molecular sieve membranes with well-controlled nano- and micro-pores and single zinc atoms and clusters well-dispersed inside the nanopores, via the carbonization of supramolecular mixed matrix materials containing amorphous and crystalline zeolitic imidazolate framework-8 (ZIF-8). Carbonization temperature is used to fine-tune pore bottlenecks of 3.3–3.8 Ǻ, allowing unprecedented H2/CO2, H2/CH4, H2/N2, and H2/C2H6 separations with excellent stability against water vapor and physical aging.