Rare earth La single atoms supported MoO3-x for efficient photocatalytic nitrogen fixation

Herein, we demonstrate that the rare-earth La single catalyst with multi-shell characteristic is an excellent choice for this purpose. By merit of its unsaturated orbitals of La, the single La atom strongly bonds with the two-coordinated lattice oxygen on the oxygen-deficient MoO3−x to form O2c-La-O2c coordination. This robust metal-support interaction frees single atoms from detachment or aggregation, and prevents catalyst from deactivation. Meanwhile, the occupied 5d orbitals of La back-donate electrons to the 2π* molecular orbitals of adsorbed N2 that substantially activate the inert NN bond towards successive hydrogenation. And single La atom could optimize the electron property of the MoO3−x support to promote photocatalytic nitrogen fixation. Without any sacrificial agents, this single atom La catalyst with a well-designed coordination structure delivers an impressive NH3 production rate of 209.0 μmol h1 g 1 under visible light, outperforming most reported single atom photocatalysts.