Rational Design and Structural Regulation of Robust Catalysts for Electrocatalytic Hydrodechlorination: From Nanostructures to Single Atoms

As a class of persistent pollutants that are easily bioaccumulatable and highly biotoxic, chlorinated organic pollutants exist in the environment and pose a substantial threat to ecological safety. The electrocatalytic hydrodechlorination (EHDC) technology shows the advantages of high efficiency, simple operation, mild reaction conditions, and no secondary pollution and thus promises a good application prospect in the treatment of chlorine-containing pollutants. Pd-based catalysts are considered the most efficient catalysts for electroreductive dechlorination thus far, yet the reserves of Pd are scarce, and the price is often prohibitively high. The development of noble metal catalysts with high atom utilization and non-noble metal catalysts for EHDC has become a hot research topic, but relevant reviews are still lacking. In this paper, the research progress on EHDC catalysts during recent years is reviewed and the influence of catalyst microstructure regulation on the EHDC performance is discussed in detail. The regulation strategies including the regulation mechanisms of electronic effect, support effect, size effect, and coordination effect for enhancing the EHDC performance of catalysts at different scales (from nanostructures to single atoms) are summarized and proposed, which could provide guidance for the development of efficient EHDC catalysts from the atomic scale. At the end of this review, the application prospects and challenges for EHDC catalysts are also discussed.