Single-atom or atomically dispersed metal materials have
emerged
as highly efficient catalysts, but their potential as excellent supports
has rarely been reported. In this work, we prepared Mg–N–C
materials derived from annealing of a Mg-based metal–organic
framework (MOF). By introducing Pt, Mg–N–C not only
serves as a platform for anchoring Pt nanoparticles but also facilitates
the integration of Mg into the Pt face-centered cubic lattice, resulting
in the formation of highly crystalline Pt3Mg nanoalloys
via the metal–support interfacial interaction. Synchrotron
radiation-based X-ray absorption spectroscopy (XAS) enables us to
study the interfacial interaction and the surface electronic structure
of this intricate system. The formation of Pt3Mg nanoalloys
induces a downshift of the Pt d-band (gaining d-charge), as revealed
by the decrease in the Pt L3-edge white-line (WL) area
under the curve. This downshift can weaken the binding of oxygen reduction
reaction (ORR) intermediates, hence improving the ORR performance.