Low-temperature CO oxidation properties and TEM/STEM observation of Au/γ-Fe2O3 catalysts

Au/gamma-Fe2O3 catalysts with Au nanoparticles on gamma-Fe2O3 supports were prepared by the solid grinding and deposition-precipitation methods. The prepared catalysts exhibit high activity for low-temperature CO oxidation. Their catalytic activity is proportional to the total length of the perimeters of all the Au particles on the supports, indicating that the active site is located on the perimeter. The fine structure of the prepared catalysts was investigated by aberration-corrected TEM and STEM. A preferential orientation relationship was observed between Au and the gamma-Fe2O3 crystals. STEM observation revealed the atomic-scale structure of the Au(111)/gamma-Fe2O3(111) interface. (C) 2015 Elsevier Inc. All rights reserved.