In the present work, a new mesoporous adsorbent containing ferrous/cuprous ionic species (Fe–Cu/MCM-41) has been developed for selective separation of 1-butene/n-butane. Co-impregnation of Fe2+ ions with Cu+ ions within mesopores gives superior 1-butene/n-butane separation ability. Fe–Cu/MCM-41 exhibits much higher heat of adsorption for 1-butene (−23.4 kJ mol−1) compared to that of Cu/MCM-41 (−11.2 kJ mol−1), resulting in a larger adsorption amount of 1-butene over Fe–Cu/MCM-41 (4.4 mmol g−1 at 1 atm) than that over Cu/MCM-41 (2.8 mmol g−1 at 1 atm). The results indicate that Fe–Cu/MCM-41 exhibits superior π-complexation ability for 1-butene than Cu/MCM-41. Moreover, the adsorption ability of Fe–Cu/MCM-41 does not change very much upon H2-treatment at different temperatures in the range of 273 K to 473 K, revealing the excellent hydrogen tolerance of the adsorbent. Physicochemical analyses indicated that the existence of Fe2+ species prevented the oxidation and reduction of Cu+ species during the adsorbent preparation and during the separation process in the presence of a reducing gas such as hydrogen, i.e., the Fe2+ species may act as a kind of redox buffer in the Fe–Cu/MCM-41 adsorbent for improving the chemical stability of Cu+ species that are highly effective for π-complexation with olefin.
You have access to this article
Please wait while we load your content...
Something went wrong. Try again?