Fig. 2: Preparation, XRD, and TEM characterization of the catalysts.

A The procedure of the preparation of the MgO/NC-T samples; B XRD patterns of the MgO/NC-T samples; C–E TEM and AC-HAADF-STEM image (inset: the particle size distribution of MgO nanoclusters) of MgO/NC-500; (F–H) HAADF-STEM image of MgO/NC-500 and corresponding EDS elemental mapping image of Mg and O.