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Abstract Electrosynthesis of alkyl carboxylic acids upon activating stronger alkyl chlorides at low‐energy cost is desired in producing carbon‐rich feedstock. Carbon dioxide (CO₂), a greenhouse gas, has been recognized as an ideal primary carbon source for those syntheses, and such events also mitigate the atmospheric CO₂level, which is already alarming. On the other hand, the promising upcycling of polyvinyl chloride to polyacrylate is a high energy‐demanding carbon‐chloride (C−Cl) bond activation process. Molecular catalysts that can efficiently perform such transformation under ambient reaction conditions are rarely known. Herein, we reveal a nickel (Ni)‐pincer complex that catalyzes the electrochemical upgrading of polyvinyl chloride to polyacrylate in 95 % yield. The activities of such a Ni electrocatalyst bearing a redox‐active ligand were also tested to convert diverse examples of unactivated alkyl chlorides to their corresponding carboxylic acid derivatives. Furthermore, electronic structure calculations revealed that CO₂binding occurs in a resting state to yield an η²‐CO₂adduct and that the C−Cl bond activation step is the rate‐determining transition state, which has an activation energy of 19.3 kcal/mol. A combination of electroanalytical methods, control experiments, and computational studies were also carried out to propose the mechanism of the electrochemical C−Cl activation process with the subsequent carboxylation step. 

Abstract Reductive hydrodechlorination is an effective approach to enhance the degradation rate of chlorinated herbicides such as alachlor, which are frequently detected in ground and surface water. In this study, a cobalt porphyrin complex with eight triazole units and alkyl chains,CoPor8T, was synthesized to catalyze the reductive hydrodechlorination of alachlor. Mechanistic study was performed using a combination of voltametric, spectroscopic, and electrospectroscopic techniques. A conversion yield of 84 % at −1.8 V vs. Fc/Fc⁺and chloride ion concentration of 96 % was obtained after electrocatalysis. This work provides a new avenue of using molecular catalysts for electrocatalytic chlorinated herbicide remediation.