Electrocatalytic hydrodechlorination of 2,4-dichlorophenol on Pd catalysts supported on N-doped mesoporous carbons: Impact of electronic effects

The Pd catalysts supported on activated carbon (AC), ordered mesoporous carbon (CMK3) and N-doped mesoporous carbon (NCMK3) were prepared, and electrocatalytic hydrodechlorination (EHDC) of 2,4-dichlorophenol (2,4-DCP) was studied on the catalysts. The electronic properties of Pd particles in Pd/NCMK3 were modulated using varied reduction temperature. Increasing reduction temperature from 200 to 300 degrees C leads to the decrease of Pdn+/Pd-0 in Pd/NCMK3 from 1.56 to 0.83. As a result, Pd/NCMK3 reduced at 200 degrees C exhibits substantially enhanced EHDC activity for 2,4-DCP with a peak mass activity of 3.37 min(-1) mg(Pd)(-1), which is much better than previously reported catalysts. The DFT calculation shows that highly effective activation of C-Cl bonds can be achieved on cationic Pd species. Furthermore, the Pd/NCMK3 catalyst shows excellent electrocatalytic stability for EHDC of 2,4-DCP, demonstrating its great potential in the long-term application in the electrocatalytic removal of chlorinated pollutants.