Green method could enable hospitals to produce hydrogen peroxide in house

UNIVERSITY OF CALIFORNIA – SAN DIEGO

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IMAGE: THE RESEARCHERS’ H-CELL SETUP USED IN DEVELOPING THEIR HYDROGEN
PEROXIDE PRODUCTION METHOD. view more

CREDIT: ZHENG CHEN LAB

A team of researchers has developed a portable, more environmentally
friendly method to produce hydrogen peroxide. It could enable
hospitals to make their own supply of the disinfectant on demand and
at lower cost.

The work, a collaboration between the University of California San
Diego, Columbia University, Brookhaven National Laboratory, the
University of Calgary, and the University of California, Irvine, is
detailed in a paper published in Nature Communications.

Hydrogen peroxide has recently 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.

“You maybe only have just a couple of months to use it before it
expires, so you would have to order batches more frequently to keep a
fresh supply,” said UC San Diego nanoengineering professor Zheng Chen.
“And because it decomposes so quickly, shipping and storing it become
very expensive.”

Chen and colleagues 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.

“Our goal is 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,” Chen said. “No need to ship it, no need
to store it, and no rush to use it all before it expires. This could
save up to 50 to 70% in costs.”

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. “In the next step, we will
develop electrocatalysts suitable for other electrolyte solutions to
further increase the range of its applications,” said UC San Diego
chemical engineering graduate student Qiaowan Chang.

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 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.

Columbia University chemical engineering professor Jingguang Chen
said, “The coordination between oxygen-modified Pd cluster and the
oxygen-containing functional groups on carbon nanotubes is the key to
enhancing its catalytic performance.”

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.

“We had been working on this project for about one and a half years.
As we were wrapping things up, the COVID-19 pandemic hit,” Chen said.
Seeing news reports about the use of hydrogen peroxide vapor to
disinfect N95 masks for reuse motivated the team to pivot directions.

“We saw that there was a more pressing need for efforts to help health
care workers who may not have sufficient protection while caring for
patients suffering from the new coronavirus,” he said.

The work is at the proof-of-concept stage. 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, Chen said. Part of this continuing work is
currently supported by UC San Diego’s Sustainable Power and Energy
Center.

Paper title: “Promoting H2O2 Production via 2-Electron Oxygen
Reduction by Coordinating Partially Oxidized Pd with Defect Carbon.”
Co-authors include Qiaowan Chang, Pu Zhang and Hongpeng Gao, UC San
Diego; Amir Hassan Bagherzadeh Mostaghimi and Samira Siahrostami,
University of Calgary; Xueru Zhao, Brookhaven National Laboratory;
Steven R. Denny, Ji Hoon Lee and Jingguang G. Chen, Columbia
University; and Ying Zhang, Central South University, China.

This work was supported in part by the ACS Petroleum Research Fund
(59989-DNI5), the U.S. Department of Energy (DE-FG02-13ER16381) and
the UC San Diego Jacobs School of Engineering.