Enantioselective synthesis of amino acids by photocatalytic reduction of CO2 on chiral mesostructured ZnS

Abstract

Reduction and fixation of CO₂ in natural systems via solar energy generate diverse products, ranging from small molecules to biomolecules. To date, only a few multicarbon species have been obtained by artificial CO₂ photoreduction, especially abiotic photosynthesis of biomolecules with various functional groups, which is a challenging issue. Herein, we report the photocatalytic synthesis of amino acids from CO₂ and NH₃ on a chiral mesostructured ZnS (CMZ). Serine is the main component of various amino acids, with an enantiomeric excess (ee) greater than 96% and a total yield of over 30 μmol g_cat⁻¹. We propose that the chirality-induced spin polarization of CMZ boosts the creation of triplet OCCO by aligning its parallel electron spins, and the helical lattice distortion reduces the free energy of ^∗OCCO. Enantiospecific activation energies of reactions driven by the spin-polarized electrons in CMZ lead to the formation of enantiomeric amino acids.