Highly active rod-like Co3O4 catalyst for the formaldehyde oxidation reaction

•Rod-like Co3O4 was synthesized by a modified precipitation method.•Rod-like Co3O4 shows good performance on low-concentration formaldehyde removal.•Abundance of Co3 + ions on rod-like Co3O4 surface exhibits high oxidation ability.•Hydroxyl species on the surface promote the activity of formaldehyde oxidation.

In this study, rod-like Co3O4 (Co3O4-rod) nanocatalyst was prepared by a modified precipitation method, which showed an excellent performance for formaldehyde oxidation to carbon dioxide and water. The light-off temperature (10% conversion) and the temperature for complete conversion of formaldehyde was at 60 °C and 120 °C, respectively. XPS and CO2-TPD analyses indicated that Co3O4-rod had abundant Co3 + and OH (hydroxyl) species on the surface compared with other morphologies of Co3O4 investigated (e.g. Co3O4-sheet and Co3O4-cube). It was proposed that Co3 + ions should be considered as active sites of good oxidation ability for formaldehyde catalytic oxidation.

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