We study 14 atomically dispersed transition metals on halite-type oxides (MeO, Me = Fe, Mg, Mn, and Ni) using periodic density functional theory calculations and probe structure and activity toward CO oxidation for a subset of these systems experimentally. Pd and Pt can form stable negatively charged species upon binding to oxygen vacancies; the magnitude of the metal atom binding energy depends on the O vacancy formation energies of the supporting metal oxide and the lattice match between transition metal and support. The resulting oxide-supported single-atom systems catalyze CO oxidation by molecularly adsorbed O2 with intrinsic barriers as low as 36 kJ/mol for Pt/MnOx(001). This high activity stems from the single sites’ ability to stabilize surface superoxide species. Furthermore, intrinsic barriers were found to depend primarily on the identity of the transition metal and to be nearly independent of the support identity. However, O2 may heal the oxygen vacancy, which leads to catalyst deactivation. Catalyst deactivation by oxygen can be suppressed by using a more reducible support such as FeO(001) or MnO(001).
Microscopic control of macroscopic phenomena is one of the core subjects in materials science. Particularly, the spatio‐temporal control of material behaviors through a non‐contact way is of fundamental importance but is difficult to accomplish. Herein, a strategy to realize remote spatio‐temporal control of luminescence behaviors is reported. A multi‐arm salicylaldehyde benzoylhydrazone‐based aggregation‐induced emission luminogen (AIEgen)/metal‐ion system, of which the fluorescence can be gated by the UV irradiation with time dependency, is developed. By changing the metal‐ion species, the fluorescence emission and the intensity can also be tuned. The mechanism of the UV‐mediated fluorescence change is investigated, and it is revealed that a phototriggered aggregation‐induced emission (PTAIE) process contributes to the behaviors. The AIEgen is further covalently integrated into a polymeric network and the formed gel/metal‐ion system can achieve laser‐mediated mask‐free writing enabled by the PTAIE process. Moreover, by further taking advantage of the time‐dependent self‐healing property of hydrazone‐based dynamic covalent bond, transformable 4D soft patterns are generated. The findings and the strategy increase the ways to manipulate molecules on the supramolecule or aggregate level. They also show opportunities for the development of controllable smart materials and expand the scope of the materials in advanced optoelectronic applications.