Electrocatalytic Dechlorination Of 2,4-Dcba Using Ctab Functionalized Pd/Gac Movable Granular Catalyst: Role Of Adsorption In Catalysis

The CTAB-Pd/GAC catalyst was obtained by functionalizing palladium/granular activated carbon (Pd/GAC) with cetyltrimethylammonium bromide (CTAB), which was used for the electrocatalytic reductive dechlorination of 2,4-dichlorobenzoic acid (2,4-DCBA). The degradation rate of 2,4-DCBA by 40 mg g(-1) CTAB-Pd/GAC was 9.8 x 10(-3) (min(-1) g(-1) Pd), which was 11 folds than that by Pd/GAC (0.9 x 10(-3) min(-1) g(-1) Pd), and the value of q(e, 2,4-DCBA)/q(e), BA was 2.33 as compared to 0.67 for Pd/GAC. The combined result of dechlorination and adsorption experiments suggested that the functionalization by CTAB would enhance the 2,4-DCBA concentration on the surface of CTAB-Pd/GAC, and accelerate the degradation rate. However, the removal efficiency of 2,4-DCBA would decrease when the CTAB load reached 80 mg g(-1), due to the excessive adsorption capacity for dech-lorinated product. Density functional theory (DFT) calculations also proved that CTAB would increase adsorption capacity of catalyst and selective adsorption behavior of 2,4-DCBA, which accelerated the degradation rate of 2,4-DCBA.