Pd/Fe2O3 with Electronic Coupling Single-Site Pd–Fe Pair Sites for Low-Temperature Semihydrogenation of Alkynes

Dispersing single palladium atoms on a support is promising to minimize the usage of palladium and improve the selectivity for alkyne semihydrogenation, but its activity is often very low as a result of unfavorable H 2 activation. Here, we load palladium onto α-Fe 2 O 3 (012) to construct highly active and stable single-site Pd–Fe pairs with luxuriant d-electron domination near the Fermi level driven by strong electronic coupling and prove that Pd–Fe pairs cooperatively adsorb H 2 and dissociate an H─H bond, whereas solo Pd sites enable preferential desorption of C═C intermediate, thus achieving both high activity and high selectivity for alkyne hydrogenation. This catalyst exhibits state-of-the-art performance in purifying acetylene of ethylene stream, with 99.6% and 100% conversion and 96.7% and 94.7% selectivity at 353 and 393 K, respectively, and excellent stability with negligible a…