Observation of asymmetric oxidation catalysis with B20 chiral crystals

Abstract

Heterogeneous processes for enantiomeric processes based on inorganic crystals have been a topic of resurgent interest. However, it remains a challenge to answer the question of what the driving forces for the emergence of homochirality in nature and chemical reactions are. Here, we propose one possible driver of enantioselectivity, namely orbital angular momentum (OAM) polarization. Enantioselective recognition of 3,4-dihydroxyphenylalanine (DOPA) was achieved by using B20 group PdGa crystals with different chiral lattices. Orbital textures of PdGa enantiomers (namely PdGa-A and PdGa-B) suggest large OAM polarization for the bands near the Fermi level and carrying opposite signs. This leads to the difference in adsorption energy between PdGa chiral crystals and DOPA molecules, depending on the pairing ability between the O 2p and Pd 4d orbital. These results provide a new route to achieving enantioselectivity with pure inorganic crystals and may hold an answer to the origin of chirality in nature.

Chirality Induced Spin Selectivity in Chiral Crystals

“…This is probably because Pt atoms have larger atomic numbers and hence stronger SOC effects than Pd atoms. Recent studies reveal that the topological chiral semimetals such as PdGa show promising applications in enantioselective catalytic reactions of chiral molecules 17,49,50 , which is a signature of the existence of the exotic interplay between the structural chirality of the material and its electron spin or orbital transport properties 3 . Our results reveal that the presence of the specific spin and orbital polarization carried by the transmitted electrons through PdGa will facilitate the theoretical understanding of the enantioselective chemistry in the material 51 .…”