La1−xSrxFeO3 perovskite electrocatalysts for asymmetric electrocarboxylation of acetophenone with CO2. (1st December 2021) - Yang, Li-Rong
Abstract: The use of La1−x Srx FeO3 (x= 0, 0.1, 0.2, 0.3, 0.4 and 0.5) cathodes in asymmetric electrocarboxylation of acetophenone with CO2 induced by chiral auxiliary Co II -(salen) was investigated for the first time. Optically active 2-hydroxy-2-phenylpropionic acid with 94% enantiomeric excess and 68% yield were obtained. The superior asymmetric electrocarboxylation performance may derive from the Fe 4+ species and the increased lattice oxygen concentration on the surface of La0.7 Sr0.3 FeO3 (LSF-0.3) induced by Sr-doping, together with an accelerated electron transfer and an increased electrochemically active surface area. Here, perovskite oxide catalyst has an acid function, which is supplied by Fe 4+ ions, can participate in the reaction by coordinating with acetophenone. Moreover, the LSF-0.3 has considerable stability and reusability. By cyclic voltammograms and contrast experiments, a mechanism was proposed for the asymmetric electrocarboxylation reaction. Graphical abstract: Image, graphical abstract The superior asymmetric electrocarboxylation performance for La0.7 Sr0.3 FeO3 cathode may stem from the increased concentration of O 2– and Fe 4+, together with an accelerated electron transfer and an increased electrochemically active surface area.