Molecular-scale hybrid membranes: Metal-oxo cluster crosslinked benzimidazole-linked polymer membranes for superior H2 purification

Hydrogen (H-2) purification requires separation membranes with excellent performance and high stability. Here, a few nanometer-sized Zr-oxygen clusters (CP-2) abundant in amino groups were incorporated in benzimidazole-linked polymers (BILPs) by interfacial polymerization (IP) to fabricate molecular-scale hybrid membranes for efficient H-2/CO2 separation. The amino groups in CP-2 engage in IP. The structure of the BILPs polymer chains is regulated and more H-2 selective channels are created. The hybrid membranes provide an H-2/CO2 selectivity of up to 75.2 (with a corresponding H-2 permeance of 318 GPU) and a high H-2 permeance of up to 1470 GPU (with a corresponding H2/CO2 selectivity of 23.6). In addition, the membranes exhibit satisfactory separation performance and durability under industry-relevant conditions (573 K, 11 bar, or steam treatment).