Pd nanoparticles on defective polymer carbon nitride: Enhanced activity and origin for electrocatalytic hydrodechlorination reaction

For the electrocatalytic hydrodechlorination reaction of 2,4-dichlorophenol to phenol, -C≡N or -Nv defects can effectively modulate the Pd-PCN interaction and promote the preferential adsorption of 2,4-dichlorophenol, resulting in an enhanced dechlorination efficiency. [Display omitted] Here we report a facile defect-engineering strategy on the support to optimize the metal-support interaction and enhance the metal’s electrocatalytic hydrodechlorination performance in converting 2,4-dichlorophenol (2,4-DCP) to phenol. The specific activity of the Pd nanoparticles (Pd NPs) on defective polymer carbon nitride (Pd/PCN-x) reaches 0.09 min-1 m-2Pd, which is 1.5 times that of the Pd NPs supported on the perfect PCN (Pd/PCN-0). The combined experimental and theoretical results demonstrate that the strong adsorption of phenol on Pd/PCN-0 passivates the active sites, limiting the dechlorination progress. The PCN-x containing -C≡N defects can effectively mediate the spatial configuration and electronic structure of Pd NPs, and promote the preferential adsorption of 2,4-DCP rather than phenol, resulting in an enhanced dechlorination efficiency.