High-Entropy La(FeCuMnMgTi)O 3 Nanoparticles as Heterogeneous Catalyst for CO 2 Electroreduction Reaction.

In this work, La(FeCuMnMgTi)O 3 HEO nanoparticles with a perovskite-type structure are synthesized and used in the electrocatalytic CO 2 reduction reaction (CO 2 RR). The catalyst demonstrates high performance as an electrocatalyst for the CO 2 RR, with a Faradaic efficiency (FE) of 92.5% at a current density of 21.9 mA cm -2 under -0.75 V vs a saturated calomel electrode (SCE). Particularly, an FE above 54% is obtained for methyl isopropyl ketone (C 5 H 10 O, MIPK) at a partial current density of 16 mA cm -2 , overcoming all previous works. Besides, the as-prepared HEO catalyst displays robust stability in the CO 2 RR. The excellent catalytic performance of La(FeCuMnMgTi)O 3 is ascribed to the synergistic effect between the electronic effects associated with five cations occupying the high-entropy sublattice sites and the oxygen vacancies within the perovskite structure of the HEO. Finally, DFT calculations indicate that Cu plays a vital role in the catalytic activity of the La(FeCuMnMgTi)O 3 HEO nanoparticles toward C2+ products.