CuI-Embedded fiber sorbent with CO selective adsorption for High-Purity H2 recovery

Carbon monoxide (CO) removal techniques are critically important in the context of hydrogen (H₂) purification to achieve an economically viable hydrogen value chain. Herein, we develop the new type of structured sorbents, Cu^I-embedded fiber sorbents, fabricated by incorporating Cu sources into MOF/polymer composite fibers, for selective removal of CO from H₂-rich gas. Cu^I-embedded fiber sorbents show remarkable dynamic adsorption performance, 1.4 – 2.6 times greater dynamic sorption capacities than those of pure MIL-101(Cr)/PVDF fiber, across the range of CO compositions and cyclic stability under the static and/or dynamic adsorption conditions. We also confirm that the form-factor of support can influence to the aggregation effect of infused copper species. Notably, compared to the powder form sorbents, these fiber-form sorbents show enhanced copper dispersion ability, resulting in the ultrahigh Cu utilization degree. The new Cu^I active sites, identified from the in-situ CO diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis, further elucidate the highly dispersed Cu contents, implying that the formation of active metal sites with different micro-environments. This work highlights the new concepts of the adsorption-based carbon monoxide removal system with potential application for high-purity H₂ recovery.