German China

Germany: Dichloro and Dibromo Compounds Contaminated Soil Could Be Source for Valuable Chemicals

Editor: MA Alexander Stark

Scientists at Johannes Gutenberg University Mainz (JGU) and ETH Zurich have developed a process to produce commodity chemicals in a much less hazardous way than was previously possible. Such commodity chemicals represent the starting point for many mass-produced products in the chemical industry.

Related Vendor

A new process could help in eliminating toxic substances in soil and exploit them in a beneficial way.
A new process could help in eliminating toxic substances in soil and exploit them in a beneficial way.
(Source: Public Domain / Pixabay )

Mainz — Researchers of Mainz University use electrolysis to produce dichloro and dibromo compounds in a safer and more environmentally friendly manner. These basic materials can be used for the production of plastics, dyes, and fertilizers, and are usually synthesized with the help of chlorine gas or bromine, both of which are extremely toxic and highly corrosive. In the current issue of Science, the researchers report that they have been able to utilize electrolysis, i.e., the application of an electric current, to obtain chemicals known as dichloro and dibromo compounds, which can then be used to synthesize commodity chemicals. According to Professor Siegfried Waldvogel, spokesperson for JGU's cutting-edge SusInnoScience research initiative, chlorine gas and bromine are difficult to handle, especially for small laboratories, as they require strict safety procedures. The new method largely eliminates the need for safety measures because it does not require the use of chlorine gas or bromine. It also makes it easy to regulate the reaction in which the desired chemicals are synthesized by controlling the supply of electric current.

According to Waldvogel, electrolysis can be used to obtain dichloro and dibromo compounds for example from solvents that would ordinarily be used to produce PVC. This is even simpler than synthesizing dichloro and dibromo products from chlorine gas or bromine, respectively. The research team, he claims, has demonstrated that the novel process functions as intended for more than 60 different substrates. The process can be used for molecules of different sizes and is thus broadly applicable. It is also easy to scale up, and they have already been able to employ it to transform larger quantities in the multi-gram range. The chemist is particularly enthusiastic about the discovery that electrolysis can also be used to separate chlorine atoms from molecules of certain insecticides that have been banned, yielding the desired dichloro products. There is virtually no natural degradation of such insecticides. They persist in the environment for extremely long periods and have now even been detected in the Arctic. This process could help in eliminating such toxic substances and actually exploit them in a beneficial way.

Original publication: X. Dong et al., Merging shuttle reactions and paired electrolysis for reversible vicinal dihalogenations, Science, 29 January 2021