Catalytic hydrodechlorination of chlorobenzene over supported palladium catalyst in buffered medium
The catalytic hydrodechlorination (HDC) reaction, which is an attractive abatement process for chlorinated organic wastes, was studied over a magnetically recoverable supported Pd(0) catalyst. We investigated the most favorable reaction conditions under which to obtain the highest substrate conversion rates while preserving the catalyst properties and morphology. Sodium hydroxide, triethylamine and buffered solutions were used as proton scavengers in the HDC of chlorobenzene under mild conditions. It was observed that sodium hydroxide caused corrosion of the silica support, triethylamine in 2-propanol preserved the morphology of the catalyst which could be recycled for up to five successive HDC reactions, and aqueous buffer solutions preserved the catalyst morphology and the catalytic activity for up to four successive HDC reactions. The use of buffer solutions to neutralize the HCl formed during the HDC reaction is an interesting, less aggressive, alternative approach to HDC reactions.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights▶ Complete conversion of chlorobenzene to benzene under mild reaction conditions. ▶ Easy catalyst recovery by simply applying an external magnetic field. ▶ Catalytic hydrodechlorination reaction performed in neutral aqueous medium. ▶ Possibility of reusing the catalyst in successive reactions. ▶ Negligible leaching of Pd and Fe into the products.
Journal: Applied Catalysis B: Environmental - Volume 100, Issues 1–2, 11 October 2010, Pages 42–46