Biomimetic Au/CeO(2) Catalysts Decorated with Hemin or Ferrous Phthalocyanine for Improved CO Oxidation via Local Synergistic Effects

Biomimetic catalysts have drawn broad research interest owing to both high specificity and excellent catalytic activity. Herein, we report a series of biomimetic catalysts by the integration of biomolecules (hemin or ferrous phthalocyanine) onto well-defined Au/CeO(2), which leads to the high-performance CO oxidation catalysts. Strong electronic interactions among the biomolecule, Au, and CeO(2) were confirmed, and the CO uptake over hemin-Au/CeO(2) was roughly about 8 times greater than Au/CeO(2). Based on the Au/CeO(2)(111) and hemin-Au/CeO(2)(111) models, the density functional theory calculations reveal the mechanisms of the biomolecules-assisted catalysis process. The theoretical prediction suggests that CO and O(2) molecules preferentially bind to the surface of noncontacting Au atoms (low-coordinated sites) rather than the biomolecule sites, and the accelerating oxidation of Au-bound CO occurs via either the Langmuir-Hinshelwood mechanism or the Mars-van Krevelen mechanism. Accordingly, the findings provide useful insights into developing biomimetic catalysts with low cost and high activity.