Chemical Engineering @ChemengFiles.Com

Researchers at the Institute of Chemical Technology, the Joint Council for Scientific Research (CSIC) and Universidad Politécnica de Valencia, have patented a new catalyst based on gold nanoparticles that are capable of carrying out the reaction for the formation of aromatic azocompuestos without generating toxic waste. These molecules are used as coloring agents, food additives and pharmaceuticals.

At work, which is published in the latest issue of the journal Science, scientists have been facing a problem that has chemical interest from the standpoint of basic research and its implications for industrial and social get azocompuestos so environmentally responsible.

As the researcher CSIC Avelino Corma: "So far, these molecules were obtained by a non-catalytic route for the use of lead compounds or nitrites. In this way we could say that was generated from one kilogram for every kilogram of product desired product. With this new catalyst that uses air as the oxidizing reagent generates only water as a byproduct. "

In addition, the new catalyst achieves an almost total conversion to the desired product and reduces the process that is usually done in three stages to a single step. "The new process is shorter by a possible reduction with H2, followed by oxidation with air, which also produces a significant cost savings," says Corma.

The finding has a clear industrial applicability and sustainability has attracted the attention of a Spanish company that is studying the process and with the Institute of Chemical Technology, which has patented the process, has signed an agreement.

Within what is considered sustainable chemistry is towards the intensification of processes in order to reduce the number of steps needed to obtain the desired products. To Corma: "Often, the synthesis of a final product requires the synthesis of several intermediates. In this case, the production of each intermediate product would also require further stages of separation and purification with consequent additional costs of investment and energy consumption .

"It seems clear then that if a good catalyst for carrying out a reaction, minimizing the energy consumption of the process, using best raw materials or reagents, and no reaction products are obtained that need to be removed or transformed into other . This is not a product to avoid having to remove them, "concludes the researcher CSIC.