Original- “Reductive Dechlorination”
Electrochemical[edit]
The electrochemical reduction of chlorinated chemicals such as chlorinated hydrocarbons and chlorofluorocarbons (CFCs) can be carried out by electrolysis in appropriate solvents, such as mixtures of water and alcohol. The cathode transfers electrons to the molecule, which decomposes to produce the corresponding hydrocarbon (hydrogen atoms substitute the original chlorine atoms) and free chloride ions. For instance, the reductive dechlorination of CFCs is complete and produces several HFCs plus chloride.[6]
Edit- "Reductive Dechlorination"
Electrochemical[edit]
The electrochemical reduction of chlorinated chemicals such as chlorinated hydrocarbons and chlorofluorocarbons (CFCs) can be carried out by electrolysis in appropriate solvents, such as mixtures of water and alcohol. Some of the key components of an electrolytic cell are types of electrodes, electrolyte mediums, and use of mediators. The cathode transfers electrons to the molecule, which decomposes to produce the corresponding hydrocarbon (hydrogen atoms substitute the original chlorine atoms) and free chloride ions. For instance, the reductive dechlorination of CFCs is complete and produces several HFCs plus chloride.[6]
Hydrodechlorination (HDC) is a type of reductive dechlorination that is useful due to its high reaction rate. It uses H2 as the reducing agent over a range of potential electrode reactors and catalysts.[1] Amongst the types of catalysts studied such as precious metals (Pt, Pd, Rh), transition metals (Ni and Mo), and metal oxides, a preference for precious metals overrides the others.[2] As an example, palladium (Pd) often adopts a lattice formation which can easily embed hydrogen gas making it more accessible to be readily oxidized.[3] However a common issue for HDC is catalyst deactivation and regeneration. As catalysts are depleted, chlorine poisoning on surfaces can sometimes be observed, and on rare occasions, metal sintering and leeching occurs as a result.[2]
Electrochemical reduction can be performed at ambient pressure and temperature.[4] This will not disrupt microbial environments or raise extra cost for remediation. The process of dechlorination can be highly controlled to avoid toxic chlorinated intermediates and byproducts such as dioxins from incineration. Trichloroethylene (TCE) and perchloroethylene (PCE) are common targets of treatment which are directly converted to environmentally benign products. Chlorinated alkenes and alkanes are converted to hydrogen chloride (HCl) which is then neutralized with a base.[2] However, even though there are many potential benefits to adopting this method, research have mainly been conducted in a laboratory setting with a few cases of field studies making it not yet well established.
 | This is a user sandbox of Kelly Fu. You can use it for testing or practicing edits. This is not the sandbox where you should draft your assigned article for a dashboard.wikiedu.org course. To find the right sandbox for your assignment, visit your Dashboard course page and follow the Sandbox Draft link for your assigned article in the My Articles section. |
- ^ Hoke, Jeffrey B.; Gramiccioni, Gary A.; Balko, Edward N. (1992-12-15). "Catalytic hydrodechlorination of chlorophenols". Applied Catalysis B: Environmental. 1 (4): 285–296. doi:10.1016/0926-3373(92)80054-4.
- ^ a b c Ju, Xiumin (2005). "Reductive Dehalogenation of Gas-phase Trichloroethylene using Heterogeneous Catalytic and Electrochemical Methods". University of Arizona Campus Repository. hdl:10150/193594. Retrieved 8 October 2017.
- ^ Cheng, I. Francis; Fernando, Quintus; Korte, Nic (1997-04-01). "Electrochemical Dechlorination of 4-Chlorophenol to Phenol". Environmental Science & Technology. 31 (4): 1074–1078. doi:10.1021/es960602b. ISSN 0013-936X.
- ^ Tarr, Matthew (2003). Chemical Degradation Methods for Wastes and Pollutants. CRC Press. pp. 212–213. ISBN 0203912551.