Facile Decoration of Ultra-fine Pd Nanoparticles on Co(OH)2 Nanowire Arrays via an Etching-deposition Process for Highly Efficient Electrocatalytic Hydrodechlorination of 2,4-dichlorophenol

Designing an efficient Pd-based catalyst with high atom utilization efficiency is a pressing priority, presenting a significant challenge for the practical deployment of electrocatalytic hydrodechlorination (EHDC), a promising method for degrading hazardous chlorophenols (CPs). Herein, a hybrid Pd/Co(OH)2/NF electrode for the dechlorination of 2,4- dichlorophenol (2,4-DCP) is fabricated by a newly developed etching-deposition approach. Physical characterizations demonstrate that ultra-fine Pd nanoparticles (1.57 +/- 0.29 nm) accompany with Pd2+ hydroxides are uniformly deposited on the surface of Co(OH)2 nanowire arrays. EHDC tests on Pd/Co(OH)2/NF show an impressive catalytic performance with a 94.5% removal efficiency within 2 h, fast reaction kinetics (0.024 min- 1) and remarkable current efficiency (55.4%), highly competitive with literature reports. Mechanism investigations indicate that the even distribution of Pd nanoparticles and coexistence of Pd2+ sites facilitate the production of active H* and activation of C-Cl, contributing to the improvement of activity.