Catalytic nature of under- and hetero-coordinated atoms resolved using zone-selective photoelectron spectroscopy (ZPS)

• ZPS collects zone-selective, quantitative information of electronic binding energy.
• Graphite monolayer skin exhibits entrapment but point defect polarization.
• Pt adatoms and CuPd alloy serve as acceptor-type catalysts because of entrapment.
• Rh adatoms and AgPd alloy serve as donor-type catalysts because of polarization.

We present an approach for distillation of the coordination-resolved electronic binding energy and bond relaxation dynamics, which has enabled clarification of the catalytic nature of under- and hetero-coordinated atoms. It is classified that Pt adatoms and CuPd alloy serve as acceptor-type catalysts because of the bond-order-deficiency induced quantum entrapment while Rh adatoms and AgPd alloy serve as donor-type catalysts because of the polarization of the conduction electrons of the adatoms by the densely, locally entrapped core electrons. This technique also enables the distillation of the polarized electronic states of graphite point defects and the entrapped states of the monolayer skin of graphite, which may serve, respectively, donor- and acceptor-type catalyst. The developed approach complements scanning tunneling microscopy/spectroscopy and photoelectron spectroscopy for the atomistic, local, and quantitative information of bond and electronic relaxation dynamics.