Catalytic removal of chlorinated compounds over ordered mesoporous cobalt oxides synthesised by hard-templating

- Various nanocasted Co3O4 samples were evaluated for 1,2-dichloroethane oxidation.
- SBA-15 derived nanorods showed an excellent behaviour.
- This morphology was characterised by a high abundance of adsorbed oxygen species.
- {220} exposed planes were shown to be catalytically active.
- A remarkable stability was found with prolonged time on stream (120 h).

This work evaluates the catalytic behaviour of a series of mesoporous bulk cobalt oxide prepared by hard-templating using SBA-15, SBA-16 and SBA-3. In addition, a bulk catalyst obtained by silica aquagel confined precipitation is also examined. The oxidation of 1,2-dichloroethane has been selected as a model reaction for determining their suitability for the efficient removal of chlorinated pollutants in gaseous waste streams.The catalytic behaviour is found to depend on the abundance of surface adsorbed oxygen species and a good low-temperature reducibility. These key physico-chemical properties are optimised for nanocasted Co3O4 prepared by using SBA-15 as hard template. This sample is characterised by a relatively high surface area, a nanorod-like morphology and a high quality 2D ordered mesoporous structure. At 375-400 °C this sample attains an efficient oxidation of the chlorinated feed to CO2 and HCl/Cl2 while keeping a reasonable stability with time.

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