In-Situ doping-induced crystal form transition of amorphous Pd–P catalyst for robust electrocatalytic hydrodechlorination

Abstract Developing catalysts with high activity and high atom utilization as well as exploring catalytic active sites are the biggest challenges for the electrocatalytic hydrodechlorination technology. Herein, a novel strategy of Pd crystal transformation induced by in-situ doping was proposed, and a series of amorphous Pd–P nanoparticles (NPs) with controllable coordination environment were synthesized successfully. The amorphous Pd–P NPs catalyst exhibits the highest activity for electrocatalytic hydrodechlorination and good cycling stability when the Pd–P coordination number is 3 and the Pd–Pd coordination number is 4. The 4-chlorophenol hydrodechlorination efficiency of Pd–P-60 NPs reaches 100 % within 2 h, and the mass activity is 8.58 min−1 g−1, which is 5.57 times as high as that for crystalline Pd NPs catalyst. Theoretical calculation shows that Pd–P catalyst facilitates the desorption of phenol and weakens the toxic effect on active sites. Density of states indicate that the doping of P results in a downshift of d-band center, facilitating the desorption of phenol. This work discovers the crystal effect and coordination effect of amorphous Pd–P NPs for electrocatalytic hydrodechlorination, which lays an important theoretical foundation for the design and development of high-performance Pd-based catalysts for electrocatalytic hydrodechlorination.