Electrocatalytic hydrodechlorination (EHDC) is a promising approach to safely remove halogenated emerging contaminants (HECs) pollutants. However, sluggish production dynamics of adsorbed atomic H (H* ads ) limit the applicability of this green process. In this study, bimetallic Pd–Cu@MXene catalysts were synthesized to achieve highly efficient removal of HECs. The alloy electrode (Pd–Cu@MX/CC) exhibited better EHDC performance in comparison to Pd@MX/CC electrode, resulting in diclofenac degradation efficiency of 93.3 ± 0.1%. The characterization analysis revealed that the Pd 0 /Pd II ratio decreased by forming bimetallic Pd–Cu alloy. Density functional theory calculations further demonstrated the electronic configuration modulation of the Pd–Cu@MXene catalysts, optimizing binging energies for H* and thereby facilitating H* ads production and tuning the reduction capability of H* ads . Noteably, the amounts and reduction potential of H* ads for Pd–Cu@MXene catalysts were 1.5 times higher and 0.37 eV lower than those observed for the mono Pd electrode. Hence, the introduction of Cu into the Pd catalyst optimized the dynamics of H* ads production, thereby conferring significant advantages to EHDC reactions. This augmentation was underscored by the successful application of the alloy catalysts supported by MXene in EHDC experiments involving other HECs, which represented a new paradigm for EHDC for efficient recalcitrant pollutant removal by H* ads .
High-entropy carbides (HECs) possess superior properties such as favorable corrosion resistance and marvelous hardness and are widely applied in specific extreme environments. Herein, a novel method was proposed for synthesizing HECs powders with raw materials of corresponding oxides and carbon black, which was composed of steps of ball-milling in stainless jar, carbothermic reduction at 1873 K, as well as the following calcium posttreatment at 1273 K to remove residual carbon by generating CaC 2 . Finally, pure HECs powders could be fabricated after acid leaching treatment. Under the current experimental conditions, besides HfC-TaC-ZrC-NbC quaternary system, a homogeneous solid solution could be fabricated by adding Mo or/and Ti, but it could not be achieved for systems with addition of V, W, or Cr, owing to the low lattice constant or different crystal structure of corresponding carbides. In the reduction step, iron resulted from ball milling process acted as the diffusion channel to promote the mutual diffusion of different components. Meanwhile, the calcium treatment temperature had a weak effect on particle size of HEC powders. HfC-TaC-ZrC-NbC-MoC-TiC powders prepared at the calcium posttreatment temperature of 1273 K had an oxygen content of .302% and an average grain size of 252 nm.
危险品化学品经营许可证（带存储）