θ-Al2O3/FeO1.25 possessing a special ring complex of FeII---HO===FeIII for the efficient catalytic semi-hydrogenation of acetylene under front–end conditions

Herein, we pioneered that half-reduced Fe2O3 supported on θ-Al2O3 (θ-Al2O3/FeO1.25-6%-500-450) is capable of the complete removal of acetylene (0.7 vol%), achieving 82% selectivity for ethylene under front–end conditions. Corresponding characterizations demonstrate that θ-Al2O3/FeO1.25-6%-500-450 can efficiently dissociate H2 and possesses both an appropriate adsorption capacity of acetylene and desorption capacity of ethylene, due to the presence of a special ring complex of FeIII, FeII, and hydroxyl groups (FeII---HO===FeIII). Crucially, θ-Al2O3/FeO1.25-6%-500-450 displays both excellent semi-hydrogenation performance and stability on a 750 mL industrial side-line device at Lanzhou Petrochemical Company.