title: Excited-State N2Dissociation Pathway on Fe-Functionalized Au.
abstract: Localized surface plasmon resonances (LSPRs) offer the possibility of light-activated chemical catalysis on surfaces of strongly plasmonic metal nanoparticles. This technology relies on lower-barrier bond formation and/or dissociation routes made available through energy transfer following the eventual decay of LSPRs. The coupling between these decay processes and a chemical trajectory (nuclear motion, charge-transfer, intersystem crossing, etc.) dictates the availability of these alternative (possibly lower barrier) excited-state channels. The Haber-Bosch method of NH3synthesis from N2and H2is notoriously energy intensive. This is due to the difficulty of N2dissociation despite the overall reaction being thermodynamically favorable at ambient temperatures and pressures. LSPRs may provide means to improve the kinetics of N2dissociation via induced resonance electronic excitation. In this work, we calculate, via embedded n-electron valence second-order perturbation theory within the density functional embedding theory, the excited-state potential energy surfaces for dissociation of N2on an Fe-doped Au(111) surface. This metal alloy may take advantage simultaneously of the strong LSPR of Au and the catalytic activity of Fe toward N2dissociation. We find the ground-state dissociation activation energy to be 4.74 eV/N2, with Fe as the active site on the surface. Consecutive resonance energy transfers (RETs) may be accessed due to the availability of many electronically excited states with intermediate energies arising from the metal surface that may couple to states induced by the Fe-dopant and the adsorbate molecule, and crossing between excited states may effectively lower the dissociation barrier to 1.33 eV. Our work illustrates that large energetic barriers, prohibitive toward chemical reaction, may be overcome through multiple RETs facilitating an otherwise difficult chemical process.
authors.affiliation: Department of Mechanical and Aerospace Engineering and ‡School of Engineering and Applied Science, Princeton University , Princeton, New Jersey 08544-5263, United States.
authors.forename: John Mark P
authors.initials: JM
authors.lastname: Martirez
authors.affiliation: Department of Mechanical and Aerospace Engineering and ‡School of Engineering and Applied Science, Princeton University , Princeton, New Jersey 08544-5263, United States.
authors.forename: Emily A
authors.identifier: 0000-0001-7330-7554
authors.initials: EA
authors.lastname: Carter