Hydrogen peroxide has made headlines as researchers and medical centers around the country have been testing its viability in decontaminating N95 masks to deal with shortages amid the COVID-19 pandemic. While results so far are promising, some researchers worry that the chemical’s poor shelf life could make such decontamination efforts costly.
The main problem is that hydrogen peroxide is not stable; it starts breaking down into water and oxygen even before the bottle has been opened. It breaks down even more rapidly once it is exposed to air or light. And because it decomposes so quickly, shipping and storing it become very expensive.
Researchers have developed a quick, simple, and inexpensive method to generate hydrogen peroxide in-house using just a small flask, air, an off-the-shelf electrolyte, a catalyst, and electricity.
The goal was to create a portable setup that can be simply plugged in so that hospitals and even households have a way to generate hydrogen peroxide on demand. Another advantage is that the method is less toxic than industrial processes.
The method is based on a chemical reaction in which one molecule of oxygen combines with two electrons and two protons in an acidic electrolyte solution to produce hydrogen peroxide. This type of reaction is known as the two-electron oxygen reduction reaction and it is user-friendly because it can produce dilute hydrogen peroxide with the desired concentration on demand.
The key to making this reaction happen is a special catalyst that the team developed. It is made up of carbon nanotubes that have been partially oxidized, meaning that oxygen atoms have been attached to the surface. The oxygen atoms are bound to tiny clusters of three to four palladium atoms. These bonds between the palladium clusters and oxygen atoms are what enable the reaction to occur with a high selectivity and activity due to its optimal binding energy of the key intermediate during the reaction.
The team originally developed this method to make battery recycling processes greener. Hydrogen peroxide is one of the chemicals used to extract and recover metals like copper, nickel, cobalt, and magnesium from used lithium-ion batteries. Similarly, it also makes the activation of hydrocarbon molecules more efficient, which is a critical step in many industrial chemical processes.
Moving forward, the team will work on optimizing and scaling up the method for potential use in hospitals. Future studies include modifying the method so that it can be done using a neutral electrolyte (basically a salt solution) instead of an acidic one, which would be better for household and clinical applications.