Reductive dechlorination

In one classic application, the Ullmann reaction, chloroarenes are coupled to biphenyl]]s. For example, the activated substrate 2-chloronitrobenzene is converted into 2,2'-dinitrobiphenyl with a copper - bronze alloy.

[3] Vicinal reduction involves the removal of two halogen atoms that are adjacent on the same alkane or alkene, leading to the formation of an additional carbon-carbon bond.

Sometimes the bacterial species are highly specialized for organochlorine respiration and even a particular electron donor, as in the case of Dehalococcoides and Dehalobacter.

Bioremediation of these chloroethenes can occur when other microorganisms at the contaminated site provide H2 as a natural byproduct of various fermentation reactions.

The resulting monochlorobiphenyls and dichlorobiphenyls are less toxic and more easily degradable by aerobic organisms compared to their chlorinated counterparts.

Additionally, high inorganic carbon levels do not affect dechlorination rates in low PCB concentration environments.

As an example, palladium often adopts a lattice formation which can easily embed hydrogen gas making it more accessible to be readily oxidized.

As catalysts are depleted, chlorine poisoning on surfaces can sometimes be observed, and on rare occasions, metal sintering and leaching occurs as a result.

The process of dechlorination can be highly controlled to avoid toxic chlorinated intermediates and byproducts such as dioxins from incineration.

[22] 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.