Novel method developed to supply hydrogen peroxide with out emitting carbon dioxide

A examine revealed in ACS Utilized Supplies & Interfaces describes a novel methodology of manufacturing hydrogen peroxide (H₂O₂) with out emitting carbon dioxide (CO₂), one of many major greenhouse gases and one of many world’s most generally produced chemical substances.

Hydrogen peroxide is used to bleach cloth, pulp and paper, and to whiten enamel. It is usually used as a thruster gas for satellite tv for pc perspective management, and as a disinfectant or sterilizing agent by hospitals. Some 2 million metric tons of the compound are produced yearly.

“To know the influence of our findings, it is vital at the beginning to remember the importance of H₂O₂ within the chemical trade and the best way it is at present produced,” mentioned Ivo Freitas Teixeira, a professor of chemistry on the Federal College of São Carlos (UFSCar) in São Paulo State, Brazil. He has a Ph.D. in inorganic chemistry from the College of São Paulo (USP) and was a Humboldt Fellow on the Max Planck Institute of Colloids and Interfaces in Potsdam, Germany, between 2019 and 2021.

“All this peroxide is produced by a course of that entails anthraquinone [a compound derived from hydrolysis of anthracene, a toxic substance]. On this course of, anthraquinone is lowered after which oxidized to make H₂O₂. The drawbacks of the tactic are the excessive value of anthraquinone and using valuable metals akin to Pd [palladium], and H₂ [hydrogen] as decreasing brokers. This hydrogen is produced by steam-methane reforming, which entails excessive temperatures and releases CO₂, contributing to international warming,” he mentioned.

Within the examine, the researchers produced peroxide from oxygen (O₂) utilizing photocatalysis to information the method. In photocatalysis, the catalysts (substances that speed up the chemical response) are activated by seen gentle as an alternative of excessive temperature or strain. One other benefit of their methodology was using carbon nitride as a photocatalyst.

This materials consists solely of carbon and nitrogen, each of that are ample in Earth’s crust, and might be activated within the seen area, which corresponds to about 45% of the photo voltaic spectrum. It’s subsequently possible that daylight can be utilized as an alternative of synthetic lighting, making the method cheaper.

After testing totally different response situations, the researchers arrived at a system with a superb charge of H₂O₂ manufacturing. “We achieved O₂ discount through a photocatalytic route by which the hydrogen supply was the water within the response medium or the sacrificial reagent, sometimes glycerol, a byproduct of biodiesel manufacturing,” Teixeira defined.

On this system, carbon nitride is used as a semiconductor to separate expenses when bathed in gentle, selling discount and oxidation reactions. The O₂ is lowered to H₂O₂ and the sacrificial reagent (glycerol) is oxidized. The H₂O₂ is obtained with out the necessity to use H₂ and therefore with out CO₂ emissions.

“The highway we needed to journey in our investigation till we arrived on the outcomes described within the revealed article was an extended one as a result of we found that similtaneously H₂O₂ was produced on the floor of the photocatalyst, it is also degraded,” Teixeira mentioned.

“We needed to carry out a number of exams and preserve modifying the photocatalyst to be able to promote the formation of H₂O₂ and keep away from its decomposition. Understanding the mechanism whereby H₂O ₂ decomposes on the floor of carbon nitride was extraordinarily vital to allow us to develop the best photocatalyst for this response.”