Morphology effects of Co3O4 on the catalytic activity of Au/Co3O4 catalysts for complete oxidation of trace ethylene

Au/Co3O4 catalysts with different morphologies (nanorods, nanopolyhedra and nanocubes) were successfully synthesized and evaluated for ethylene complete oxidation. We found that support morphology has a significant effect on catalytic activity, which is related to the exposed planes of different morphological Co3O4. HRTEM revealed the Co3O4-nanorods predominantly exposes {110} planes, while the dominant exposed planes of Co3O4-nanopolyhedra and -nanocubes are OM and {001} planes, respectively. Compared with {011} and {001} planes, {110} planes exhibit the maximum amount of oxygen vacancies, which play a major role in ethylene oxidation. Therefore, Au/Co3O4-nanorods exhibits extraordinary catalytic activity, yielding 93.7% ethylene conversion at 0 degrees C. (C) 2011 Elsevier B.V. All rights reserved.