Theoretical investigation on catalytic electrooxidation of CO by Rh(III) complexes: Insight from molecule-surface interaction

Some RhIII complexes with planar ligands exhibit high catalytic activity in the electrochemical oxidation of CO. However, the mechanism is unclear, and physical-chemical studies are necessary to design complexes. In this study, we experimentally confirmed that the activity of RhIII phthalocyanine on graphite is significantly lower than other complexes, and investigated this difference theoretically. The RhIII-phthalocyanine/graphite has nonbonding orbitals even in the unoccupied region and too deep lowest unoccupied energy level. This study demonstrates the importance of optimising complex-support interactions.