Two-dimensional confined polyoxometalate-based chiral electrode for high-performance enantioselective electrocatalytic oxidation

Developing chiral electrode catalysts for asymmetric electrocatalysis is a great challenge, since catalysts with both high activity and enantioselectivity are required. Here, we fabricated a chiral polyoxometalate-based electrode material (R-CP@iGO) by confining the highly active chiral (R-BPEA)5PMo10V2O40 (R-CP) into the 2D interlayer of ionic liquid-pillared graphene oxide (iGO). The R-CP@iGO chiral electrode achieved excellent performance for asymmetric electro-oxidative kinetic resolution of racemic secondary alcohols with up to 96.5% enantiomeric excess (ee), 32.1 selectivity factors (S), and high catalytic activity of 10 mA cm−2 catalytic current density. The 2D confinement effect played a crucial role in the enantioselectivity enhancement because it can facilitate the chiral induction from the chiral (+)-bis[(R)-1-phenylethyl]amine (R-BPEA) to the catalytic active V–O sites in [PMo10V2O40]5−. Moreover, it can promote configurational adsorption discrimination toward racemic secondary alcohols, resulting in nearly all of the (S)-1-phenylethanol being absorbed and consumed, whereas the desired (R)-1-phenylethanol is retained.