A Multi-Technique Study of C2H4 Adsorption on a Model Single-Atom Rh1 Catalyst

Abstract

Single-atom catalysts are potentially ideal model systems to investigate structure-function relationships in catalysis, if the active sites can be uniquely determined. In this work, we study the interaction of C2H4 with a model Rh/Fe3O4(001) catalyst that features 2-, 5-, and 6-fold coordinated Rh adatoms, as well as Rh clusters. Using multiple surface-sensitive techniques in combination with calculations of density functional theory (DFT), we follow the thermal evolution of the system and disentangle the behavior of the different species. C2H4 adsorption is strongest at the 2-fold coordinated Rh1 with a DFT-determined adsorption energy of -2.26 eV. However, desorption occurs at lower temperatures than expected because the Rh migrates into substitutional sites within the support, where the molecule is more weakly bound. Adsorption at the 5-fold coordinated Rh sites is predicated to -1.49 eV, but the superposition of this signal with that from small Rh clusters and additional heterogeneity leads to a broad C2H4 desorption shoulder in TPD above room temperature.

References in corpus (14)

• Van der Waals density functionals applied to solids
• SCAN+rVV10: A promising van der Waals density functional
• Unravelling CO adsorption on model single-atom catalysts
• Subsurface Cation Vacancy Stabilization of the Magnetite (001) Surface
• Ordered Array of Single Adatoms with Remarkable Thermal Stability: Au/Fe3O4(001)
• Ordered Array of Single Au Adatoms with Remarkable Thermal Stability: Au/Fe3O4(001)
• An Atomic-Scale View of CO and H2 Oxidation on a Pt-Fe3O4 Model Catalyst
• Surface properties of the clean and Au/Pd covered Fe${}_3$O${}_4$(111): a DFT and DFT+$U$ study
• A Multi-Technique Study of $C{O}_2$ Adsorption on $F{e}_3$$O_4$ Magnetite
• The role of surface defects in the adsorption of methanol on Fe3O4(001)
• Real Space Imaging of the Verwey Transition at the (100) Surface of Magnetite
• Influence of Local Defects on the Dynamics of O-H Bond Breaking and Formation on a Magnetite Surface
• Charge order at magnetite Fe3O4(001): surface and Verwey phase transitions
• Fast low-noise transimpedance amplifier for scanning tunneling microscopy and beyond