16.07.2024
Study
Engineers have developed a revolutionary method for producing hydrogen gas in a one-step process
This method requires only light and no external heating.
Known for its rotten egg flavor, hydrogen sulfide is known to be highly poisonous and corrosive, especially in wastewater. Petrochemical plants and other industries produce thousands of tons of this gas every year as a byproduct of various processes that separate sulfur from oil, natural gas, coal, and other products.
Now, engineers and scientists at Rice University have invented a new way for such petrochemical industries to convert the harmful gas into “high demand” hydrogen.
Rice engineer, physicist, and chemist Naomi Halas and her team have created a method that derives energy from light and uses gold nanoparticles to convert hydrogen sulfide and sulfur in a single step.
By comparison, modern refineries with catalytic technology operate using a method known as the Claus process, which requires several steps. In addition, it produces sulfur but does not produce hydrogen, which is converted to water.
“Hydrogen sulfide emissions can lead to heavy fines for industry, but remediation is also very expensive,” said Halas, a nanophotonics pioneer whose lab has spent years developing commercially viable light-activated nanocatalysts, in a statement. “The phrase ‘game changer’ is overused, but in this case it is appropriate. The introduction of plasmonic photocatalysis should be much cheaper than traditional reduction, and it has the added potential to turn an expensive burden into an increasingly valuable commodity.”
According to Galas, the process is economical; it can have low implementation costs and high efficiency for the treatment of non-industrial hydrogen sulfide from sources such as sewer gas and animal waste.
The remediation process is economical and efficient
According to the release, the team dotted the surface of the silica powder grains with tiny “islands” of gold. Each island was a gold nanoparticle that interacted with a wavelength of visible light. The reactions created “hot carriers,” short-lived, high-energy electrons that can trigger catalysis.
In a laboratory setup, the team demonstrated that a bank of LED lamps could induce “hot carrier photocatalysis” and convert H2S directly into H2 gas and sulfur.
“Given that it requires only visible light and no external heating, the process should be relatively easy to scale up using renewable solar power or high-efficiency solid-state LED lighting,” Halas added.
Their results are published in the American Chemical Society’s journal ACS Energy Letters.