Active site and adsorption behavior engineering of subsize PdNi nanoparticles for boosting electrocatalytic hydrodechlorination of 4-chlorophenol

Developing an efficient strategy to engineer the removal efficiency of catalysts for electrocatalytic hydrodechlorination (ECH) of acute toxic chlorophenols is of considerable importance but remains challenging. We report herein an efficient strategy to modulate the active site and adsorption behaviors of PdNi alloy nanoparticles (NPs) anchored on oxygen/nitrogen-doped porous carbon nanosheets (PdNi/NPCNs) through nanopore trapping. The competitive adsorption of PdCl42- and Ni2+ ions and subsequent reduction belowrmodynamic reduction temperature ensure the formation of highly dispersed subsize PdNi alloy NPs on the surface of NPCNs. More significantly, alloying of Pd with Ni not only provides abundant surface-active sites but also adjusts the adsorption behaviors of intermediates over PdNi/NPCNs because of the strong electronic interaction between the two metals, thereby considerably boosting the ECH performance for 4-chlorophenol (4-CP) removal. The complete removal of 4-CP (100 mg L−1) is achieved at 7.5 mA within 180 min, superior to that of monometallic Pd/NPCNs and many previous electrodes reported thus far. The catalyst also exhibits boosted stability toward the ECH of 4-CP with five successive recycling runs. This study provides an effective strategy to fabricate high-performance electrocatalysts for ECH reaction, which shows great promise in potential applications.