Understanding the facet-dependent catalytic performance of hematite microcrystals in a CO oxidation reaction

Abstract

Hematite (α-Fe₂O₃) with well-defined plate, cube and rod morphologies has been successfully synthesized, which predominantly exposes the (001), (012) and (110) facets, respectively. Rod-like α-Fe₂O₃ with exposed (110) facets showed a greater CO catalytic activity than catalysts with all other morphologies. X-ray photoelectron spectroscopy (XPS) results and theoretical calculation analysis revealed that the different catalytic activities over the catalysts with various morphologies could be attributed to various catalytic mechanisms caused by different surface structures, leading to different activation energies in CO oxidation catalysis by α-Fe₂O₃ (001), (012) and (110) facets.