An innovative process for manufacturing hydrogen peroxide (H2O2) without releasing carbon dioxide (CO2), one of the principal greenhouse gases and one of the most frequently generated chemicals in the world, is described in a paper published in ACS Applied Materials & Interfaces.
To whiten teeth and bleach pulp and paper, hydrogen peroxide is employed. Additionally, it is employed by hospitals as a disinfectant or sterilising agent as well as a fuel for thrusters used in satellite attitude control. Every year, over 2 million metric tonnes of the substance are produced.
Ivo Freitas Teixeira, a professor of chemistry at the Federal University of So Carlos (UFSCar) in So Paulo State, Brazil, said, “It’s vital to keep in mind the relevance of H2O2 in the chemical industry and the manner it’s presently generated in order to appreciate the effect of our results. From 2019 to 2021, he served as a Humboldt Fellow at the Max Planck Institute of Colloids and Interfaces in Potsdam, Germany. He has a Ph.D. in inorganic chemistry from the University of So Paulo (USP).
“Anthracene, a poisonous chemical that is hydrolyzed to form anthraquinone, is used in a method that creates all of this peroxide. Anthraquinone is reduced in this procedure, and it is oxidised to produce H2O2. The method’s disadvantages include the expensive cost of anthraquinone and the usage of pricey metals as reducing agents, such as palladium and hydrogen. Steam-methane reforming, which entails high temperatures and generates CO2 to contribute to global warming, is used to make this hydrogen “explained he.
In the study, photocatalysis was used to direct the production of peroxide from oxygen (O2). In photocatalysis, rather of using high pressure or temperature to activate the catalysts (materials that speed up the chemical process), visible light is used. Their technique has the added benefit of using carbon nitride as a photocatalyst. This substance can be activated in the visible area, which makes up roughly 45% of the solar spectrum, and is made up solely of nitrogen and carbon, both of which are plentiful in the crust of the Earth. Therefore, it is likely that sunlight may be employed in place of electric illumination, increasing the efficiency of the procedure.
After experimenting with various reaction parameters, the researchers discovered a system that produced H2O2 at an exceptional rate. According to Teixeira, “We accomplished O2 reduction using a photocatalytic method in which the hydrogen source was either the water in the reaction media or the sacrificial reagent, often glycerol, a byproduct of biodiesel manufacture.
When exposed to light, carbon nitride functions as a semiconductor in this environment, separating charges and facilitating reduction and oxidation processes. As a result, the sacrificial agent (glycerol) is oxidised and the O2 is reduced to H2O2. Without the usage of H2 and hence without CO2 emissions, H2O2 is produced.
According to Teixeira, “the path we had to walk in our research until we arrived at the findings stated in the published paper was a long one since we found that at the same time that H2O2 was formed on the surface of the photocatalyst, it could also be degraded.”
“To encourage the creation of H2O2 and prevent its breakdown, we had to run a number of experiments and constantly change the photocatalyst. It was crucial for us to comprehend the process of H2O 2 decomposition on the surface of carbon nitride in order to create the optimal photocatalyst for this reaction.”
You might also be interested in reading, A Compact, Practical Mosquito Repellent Gadget Is Successful In Protecting Military Troops
