[18a-431B-1~8] 6.5 Surface Physics, Vacuum

[18a-431B-5] Theoretical investigation on the interaction between Rh^III octaethylporphyrin and a graphite basal surface

〇Kohei Tada¹, Yasushi Maeda¹, Ozaki Hiroyuki¹, Shingo Tanaka¹, Shin-ichi Yamazaki¹ (1.AIST)

Keywords:density functional theory, catalyst for CO-tolerant anode, interaction between molecule and surface

Using density functional theory based calculations mainly, we investigated the interaction between [Rh^III(OEP)(Cl)] (OEP = octaethylporphyrin) and a graphite basal surface, and the electronic structure of [Rh^III(OEP)(Cl)]/graphite. Because the [Rh^III(OEP)(Cl)] complex does not have a singlet occupied molecular orbital on the porphyrin ring, the π-π stacking interaction between porphyrin and graphite is not present and their interaction is dominated by dispersion forces. The lowest unoccupied molecular orbital (band) of [Rh^III(OEP)(Cl)]/graphite is a σ bonding orbital between Rh^III and graphite that will cause fast electron transfer from [Rh^III(OEP)(Cl)] to graphite during the CO electro-oxidation; this would be a reason why the carbon-supported [Rh^III(OEP)(Cl)] has high catalytic activity for CO electro-oxidation.